2010 California Building Code
Building Standards Commission Logo

California Code of Regulations
Title 24, Part 2, Volume 2 of 2

California Building
Standards Commission

Based on the 2009 International Building Code®

Public Domain Mark

EFFECTIVE DATE: January 1, 2011

(For Errata and supplements, See History Note Appendix)

Public Domain: U.S. Court of Appeals, Fifth Circuit, 99-40632

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2010 California Existing Building Code

California Code of Regulations, Title 24, Part 10

First Printing: June 2010

ISBN 978-1-58001-974-3

Copyright © 2010
Held by

California Building Standards Commission
2525 Natomas Park Drive, Suite 130
Sacramento, CA 95833-2936

ALL RIGHTS RESERVED. This 2010 California Existing Building Code contains substantial copyrighted material from the 2009 International Existing Building Code, which is a copyrighted work owned by the International Code Council, Inc. Without advance written permission from the copyright owner, no part of this book may be reproduced, distributed or transmitted in any form or by any means, including, without limitation, electronic, optical or mechanical means (by way of example and not limitation, photocopying, or recording by or in an information storage retrieval system). For information on permission to copy material exceeding fair use, please contact: Publications, 4051 West Flossmoor Road, Country Club Hills, IL 60478. Phone 1-888-ICC-SAFE (422-7233).

Trademarks: “International Code Council,” the “International Code Council” logo and the “International Existing Building Code” are trademarks of the International Code Council, Inc.

PRINTED IN THE U.S.A

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PREFACE

This document is Part 2 of 12 parts of the official triennial compilation and publication of the adoptions, amendments and repeal of administrative regulations to California Code of Regulations, Title 24, also referred to as the California Building Standards Code. This Part is known as the California Building Code.

The California Building Standards Code is published in its entirety every three years by order of the California legislature, with supplements published in intervening years. The California legislature delegated authority to various state agencies, boards, commissions and departments to create building regulations to implement the State’s statutes. These building regulations or standards, have the same force of law, and take effect 180 days after their publication unless otherwise stipulated. The California Building Standards Code applies to occupancies in the State of California as annotated.

A city, county or city and county may establish more restrictive building standards reasonably necessary because of local climatic, geological or topographical conditions. Findings of the local condition(s) and the adopted local building standard(s) must be filed with the California Building Standards Commission to become effective and may not be effective sooner than the effective date of this edition of California Building Standards Code. Local building standards that were adopted and applicable to previous editions of the California Building Standards Code do not apply to this edition without appropriate adoption and the required filing.

Should you find publication (e.g., typographical) errors or inconsistencies in this code or wish to offer comments toward improving its format, please address your comments to:

California Building Standards Commission
2525 Natomas Park Drive, Suite 130
Sacramento, CA 95833–2936

Phone: (916) 263-0916
FAX: (916) 263-0959

Web Page: www.bsc.ca.gov

ACKNOWLEDGMENTS

The 2010 California Building Standards Code (Code) was developed through the outstanding collaborative efforts of the Department of Housing and Community Development, the Division of State Architect, the Office of the State Fire Marshal, the Office of Statewide Health Planning and Development, the California Energy Commission, and the Building Standards Commission (Commission).

This collaborative effort included the assistance of the Commission’s Code Advisory Committees and many other volunteers that worked tirelessly to assist the Commission in the production of this Code.

Governor Arnold Schwarzenegger

Members of the Building Standards Commission

Acting Secretary Tom Sheehy – Chair

Isam Hasenin
Christina Jamison
James Barthman
Stephen Jensen
Craig Daley
Michael Paravagna
Susan Dowty
Richard Sawhill
Tony Hoffman
Steven Winkel

David Walls – Executive Director

Thomas Morrison – Deputy Executive Director

For questions on California state agency amendments; please refer to the contact list on the following page.

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California Code of Regulations, Title 24

California Agency Information Contact List
California Energy Commission
Energy Hotline(800) 772-3300 or (916) 654-5106
Building Efficiency Standards
Appliance Efficiency Standards
Compliance Manual/Forms
California State Lands Commission
Marine Oil Terminals(562) 499-6317
California State Library
Resources and Information(916) 654-0261
Government Publication Section(916) 654-0069
Corrections Standards Authority
Local Adult Jail Standards(916) 324-1914
Local Juvenile Facility Standards(916) 324-1914
Department of Consumer Affairs—Acupuncture Board
Office Standards(916) 445-3021
Department of Consumer Affairs—Board of Pharmacy
Pharmacy Standards(916) 574-7900
Department of Consumer Affairs—Bureau of Barbering and Cosmetology
Barber and Beauty Shop and(916) 574-7570
College Standards(800) 952-5210
Department of Consumer Affairs—Bureau of Home Furnishings and Thermal Insulation
Insulation Testing Standards(916) 574-2041
Department of Consumer Affairs—Structural Pest Control Board
Structural Standards(800) 737-8188
 (916) 561-8708
Department of Consumer Affairs—Veterinary Medical Board
Veterinary Hospital Standards(916) 263-2610
Department of Food and Agriculture
Meat & Poultry Packing Plant Standards(916) 654-1447
Dairy Standards(916) 654-1447
Department of Public Health
Organized Camps Standards(916) 449-5661
Public Swimming Pools Standards(916) 449-5693
Asbestos Standards(510) 620-2874
Department of Housing and Community Development
Residential—Hotels, Motels, Apartments Single-Family Dwellings(916) 445-9471
Permanent Structures in Mobilehome and Special Occupancy Parks(916) 445-9471
Factory-Built Housing, Manufactured Housing and Commercial Modular(916) 445-3338
Mobilehomes—Permits & Inspections 
Northern Region(916) 255-2501
Southern Region(951) 782-4420
Employee Housing Standards(916) 445-9471
Department of Water Resources
Gray Water Installations Standards(916) 651-9667
Division of the State Architect—Access Compliance
Access Compliance Standards(916) 445-8100
Division of the State Architect—Structural Safety
Public Schools Standards(916) 445-8100
Essential Services Building Standards(916) 445-8100
Community College Standards(916) 445-8100
Division of the State Architect—State Historical Building Safety Board
Alternative Building Standards(916) 445-8100
Office of Statewide Health Planning and Development
Hospital Standards(916) 440-8409
Skilled Nursing Facility Standards(916) 440-8409
Clinic Standards(916) 440-8409
Permits(916) 440-8409
Office of the State Fire Marshal
Code Development and Analysis(916) 445-8200
Fire Safety Standards(916) 445-8200
Fireplace Standards(916) 445-8200
Day-Care Centers Standards(916) 445-8200
Exit Standards(916) 445-8200
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EFFECTIVE USE OF THE IBC/CBC

Distilling the code review process down to a methodical, sequential list of considerations is generally problematic. In many cases, related provisions from various chapters of the code must be considered simultaneously, or reconsidered later in the process to arrive at the correct classification or determination. Any number of acceptable alternatives may exist for construction of the building and its specific features. Each choice provided by the code must be evaluated for its specific impact on other aspects of the building’s analysis. With a basic understanding of the interrelationship of the various chapters, the practiced code user will make an initial assessment of the building as a first step of the code review process. The following outline may be helpful as a guide for the effective use of the IBC, with the understanding that final resolution of each step is often dependant on subsequent steps.

The following process begins with a brief discussion of the key administrative areas of the code. The process addressing technical provisions is divided into two distinct areas of analysis, the nonstructural provisions of the IBC and the structural provisions. Although reference is not made to all provisions set forth in the IBC, the process is intended to be representative of an approach to using the IBC in an effective manner.

Administrative Provisions

Prior to any analysis based on the technical provisions of the IBC, it is important that the fundamental administrative aspects of the code be reviewed. It is critical that the basis of technical decisions be consistent with the approach established in IBC Chapter 1, including:

Nonstructural Provisions

1. Classify the building for occupancy and construction type. The first step in analyzing a building for code compliance is its proper classification based on anticipated use(s) and construction features.

Identify the distinct and varied uses of the building. The uses that will occur within the building must be identified, evaluated and classified into one or more of the distinct occupancy classifications established in the IBC. Some buildings will be classified as single-occupancy, where there is only one applicable occupancy classification. Others will be considered as mixed-occupancy due to the presence of two or more uses that are classified into different occupancy groups.

Sec. 302.1 Classify the building into one or more occupancy groups. Although there are 10 general occupancy groups, many of the groups are subdivided into sub-groups to allow for a more exacting analysis of the building under consideration.

Sec. 303Group A
Sec. 304Group B
Sec. 305Group E
Sec. 306Group F
Sec. 307Group H
Sec. 308Group I
Sec. 309Group M
Sec. 310Group R
Sec. 311Group S
Sec. 312Group U

Identify the building’s type of construction based on the materials of construction and degree of fire-resistance for the building’s major elements. The primary structural frame, exterior walls, interior walls, floor construction and roof construction, as applicable, must be evaluated in regard to their degree of fire-resistance and materials of construction in order to classify the building based upon type of construction.

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Sec. 602.1 Classify the building into a single type of construction. Five general types of construction have been established and further subdivided into nine specific construction types. The classification of construction type is based on a combination of the degree of fire-resistance and the type of materials of the key building elements.

Sec. 602Type of construction based on materials of construction
Table 601Type of construction based on fire rating of the building elements.
Sec. 603Combustible materials in Type I and II buildings

Sec. 1505 Verify classification of roof covering. Roof coverings are typically required to provide protection against moderate or light fire exposures from the exterior. Their minimum required classification is based upon the type of construction of the building.

2. Determine if the building is to be fully sprinklered. Many of the code provisions vary based upon the presence of an automatic sprinkler system throughout, or in specific portions of, the building.

Sec. 903.2 Determine if the building requires a fire sprinkler system. Many of the mandates for the installation of a sprinkler system are based upon the occupancy or occupancies that occur within the building. The provisions will often require some degree of occupant load and fire area determination. Other conditions may also trigger a required sprinkler installation, such as building height or the lack of the exterior openings. Table 903.2.13 should also be consulted.

If a sprinkler system is not required, review for potential code modifications if a sprinkler system is installed. There are a significant number of benefits provided by the code if a sprinkler system is installed. An initial analysis of the building will typically allow for an early determination of the value of such sprinkler benefits, including:

Sec. 504.2Story and height increase (reduced type of construction)
Sec. 506.3Allowable area increase (reduced type of construction)
Sec. 507.3Unlimited area building (reduced type of construction)
Sec. 1018.1Elimination of corridor fire-resistance rating

3. Locate the building on the site. The location of the building(s) on the lot is fundamental to the degree of fire exposure to and from adjoining buildings and lots. In addition, the building’s location influences the amount of fire department access that can be provided from the exterior of the building.

Sec. 503.1.2 Determine the number of buildings on the site. Where two or more buildings are located on the same lot, they can be evaluated as a single building or multiple buildings. The type of construction requirements may differ based upon which of the two methods is utilized.

Sec. 602.1 Determine minimum required fire rating of exterior walls. The fire separation distance is the measurement used in evaluating the necessary fire rating for exterior walls. It is measured from the building to the lot line, to the center line of a public way, or to an imaginary assumed line between two buildings on the same lot. Projections and parapets, if applicable, area also regulated.

Sec. 704.8 Determine exterior opening protection requirements. Openings in exterior walls are regulated by the fire separation distance and the rating of the exterior wall in which they are located.

Sec. 506.2 Determine frontage increase for allowable area purposes. Utilized primarily for fire department access, open space adjacent to a building’s perimeter provides for an increase in the allowable area.

4. Verify building’s construction type by determining the allowable building size. The permitted types of construction are primarily based upon the occupancy classifications involved, the building’s height and the building’s floor area. Other conditions may also affect the appropriate construction types, including the building’s location on the lot and the intended materials of construction. In buildings with mixed-occupancy conditions, the methods of addressing the relationship between the multiple occupancies indirectly affect construction type.

Sec. 202 and 502 Calculate actual height of building in both ‘feet’ and ‘stories above grade plane’. The code specifically describes the method for assigning a building height, measure both in the number of feet and the number of stories above grade plane. The actual height must be compared with the allowable height to determine if the building’s type of construction is acceptable.

Sec. 504 Determine allowable height permitted for ‘feet’ and ‘stories’

Sec. 505 Determine if mezzanine provisions are applicable

Sec. 504.3 Determine if any rooftop structures are in compliance

Sec. 502 Calculate actual floor area of each story of building. The building area is typically the entire floor area that occurs within the surrounding exterior walls. The building area for each individual story must be calculated, as well as for the building as a whole.

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Sec. 507 Determine if building qualifies as an unlimited area building

Sec. 506 Determine allowable area permitted for each story and building as a whole if:

Sec. 506Single-occupancy building
Sec. 508.2Multi-occupancy w/accessory occupancies
Sec. 508.3Multi-occupancy building w/nonseparated occupancies
Sec. 508.4Multi-occupancy building w/separated occupancies
Sec. 706.1Use of fire walls

Sec. 509 Determine if special provisions are to be applied for height and/or area. The general requirements for allowable height and area may be modified under limited conditions, typically where a parking garage is located in a building with other occupancies.

5. Identify extent of any special detailed occupancy requirements. Special types of buildings, special uses that occur within buildings, and special elements of a building are further regulated through specific requirements found in Chapter 4. Since these provisions are specific in nature, they apply in lieu of the general requirements found elsewhere in the code.

Chapter 4. Determine special detailed requirements based on occupancy. A number of the special provisions are applicable to a specific occupancy or group of similar occupancies.

Sec. 402Covered mall buildings
Sec. 403High-rise buildings
Sec. 404Atriums
Sec. 405Underground buildings
Sec. 406Motor-vehicle-related occupancies
Sec. 407Group I-2 occupancies
Sec. 408Group I-3 occupancies
Sec. 411Special amusement buildings
Sec. 412Aircraft-related occupancies
Sec. 415Group H occupancies
Sec. 419Live/work units
Sec. 420Group I-1, R-1, R-2 and R-3
Sec. 422Ambulatory health care facilities

Table 508.2.5 Determine if building contains any incidental accessory occupancies. The uses identified in Table 508.5.2 are considered as a portion of the occupancy in which they are located, but special conditions required that they be addressed in a more specific manner.

Sec. 508.2.5 Provide fire separation and/or fire-extinguishing system

6. Identify and evaluate fire and smoke protective elements. Where fire-resistance-rated construction and/or smoke protection is mandated by other provisions of the code, the provisions of Chapter 7 identify the appropriate methods for gaining compliance.

Chapter 7. Verify compliance w/details of fire and smoke resistance. The various elements of fire-resistance-rated and smoke-resistant construction are detailed, including walls, horizontal assemblies, shaft enclosures, including openings such as doors and windows, as well as the penetration of such elements by conduit, ducts, piping and other items.

Sec. 704Structural members
Sec. 707Fire barriers
Sec. 709Fire partitions
Sec. 710Smoke barriers
Sec. 711Smoke partitions
Sec. 712Horizontal assemblies
Sec. 708Shaft enclosures
Sec. 713Penetrations
Sec. 714Joint systems
Sec. 715Opening protectives
Sec. 716Ducts and air transfer openings
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7. Identify additional fire protection systems that may be required. In addition to automatic sprinkler systems, there are several other types of fire protection systems that may be required in a building.

Sec. 907.2. Determine compliance with fire alarm provisions. Fire alarm systems are typically mandated based upon the occupancy classification and the number of occupants.

Sec. 905.3. Determine if standpipe system is required. A standpipe system is required in buildings once a specified height is reached to provide for a more effective means of fighting a fire within the building.

Sec. 905.4.6. Verify location of standpipe hose connections.

8. Identify and evaluate materials utilized as interior floor, wall and ceiling finishes. Finish materials within the building are primarily regulated for flame spread and smoke development characteristics.

Sec. 803.9. Verify compliance of wall and ceiling finishes. Interior wall and ceiling finishes are regulated based upon the occupancy classification of the space and their location within the means of egress system. The classification may typically be reduced where sprinkler protection is provided.

Sec.804.4. Verify compliance of floor finishes. While regulated differently than wall and ceiling finishes, floor finishes comprised of fibers are also controlled based upon their use in the egress system, the occupancy classification, and the presence of a sprinkler system.

9. Evaluate means of egress system based on anticipated occupant loads. The expected occupant load is the basis for the design of the means of egress system. The egress elements must provide for a direct, continuous, obvious, undiminished and unobstructed path of travel from any occupiable point in the building to the public way.

Sec. 1004. Determine the design occupant load. Although the primary use of an occupant load is in the design of the building’s means of egress system, occupant load is also occasionally an important factor in occupancy classification, sprinkler system and fire alarm system requirements, and plumbing fixture counts.

Chapter 10. Verify compliance with means of egress provisions. The means of egress system is intended to provide the primary occupant protection from fire and other hazards. The system consists of two major components, egress components and egress design.

Sec. 1005.1Egress width and distribution
Sec. 1006.3Emergency lighting
Sec. 1007Accessible means of egress
Sec. 1008.1.2Door swing
Sec. 1008.1.9Door operations
Sec. 1008.1.10Panic hardware
Sec. 1009.1Stairway width
Sec. 1009.4Stairway treads and risers
Sec. 1011Exit signs
Sec. 1012Stairway and ramp handrails
Sec. 1013Guards
Sec. 1014.2Egress through intervening spaces
Sec. 1014.3Common path of egress travel
Sec. 1015.1Number of exit or exit access doorways
Sec. 1015.2Egress separation
Sec. 1016.1Travel distance
Sec. 1018.1Corridor construction
Sec. 1021Number of exits
Sec. 1022Vertical exit enclosures
Sec. 1023Exit passageways
Sec. 1025Horizontal exits
Sec. 1026Exterior exit stairways
Sec. 1027Exit discharge
Sec. 1028Egress from assembly occupancies
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10. Identify any special use features of the building. The activities that occur within the building pose varying risks to the occupants. Special conditions are applicable when such activities are anticipated.

Chapter 4. Verify compliance with special detailed requirements. These provisions are often an extension of the general requirements found elsewhere in the code.

Sec. 410Stages and platforms
Sec. 413Combustible storage
Sec. 414Hazardous materials
Sec. 416Application of flammable finishes

11. Determine areas of building and site required to be accessible. In general, access to persons with disabilities is required for all buildings.

Chapter 11A and/or 11B. Verify compliance with accessibility provisions. In order to be considered as accessible, buildings and their individual elements must comply with the applicable technical provisions of Chapters 11A and/or 11B.

12. Determine extent of other miscellaneous provisions. Additional provisions may be applicable based upon each individual building and its characteristics.

Sec. 2406.3. Verify safety glazing provided in hazardous locations. Safety glazing must be appropriately identified to ensure the proper glazing material is installed in areas considered as subject to human impact.

Chapter 12. Interior environment. Provisions regulating ventilation, temperature control, lighting, sound transmission, room dimensions and surrounding materials associated with interior spaces.

Chapter 14 Exterior walls. Requirements for installation of wall coverings and the permissible use of combustible materials on the exterior side of exterior walls.

Chapter 24. Glass and glazing. General provisions for the installation of glazing materials and skylights.

Chapter 30. Elevators. Elevator hoistway provisions, including enclosure of hoistways, emergency operations and hoistway venting.

Chapter 31. Special construction. A variety of special conditions are addressed, including membrane structures, temporary structures, pedestrian walkways and tunnels, awnings and canopies, marquees, signs and swimming pool enclosures.

Structural Provisions

General Requirements

  1. Design Loads.

    The 2009 IBC references the national load standard, Minimum Design Loads for Buildings and Other Structures (ASCE/SEI 7—05) with Supplement Number 2.

    Determine the applicable design loads that the building structure is expected to be subjected to. Code prescribed loads are given in Chapter 16 and the referenced standard, ASCE/SEI 7. The code prescribed minimum live loads are given in IBC Table 1607.1.

    The various code prescribed loads are probabilistic in nature. Environmental loads, such as flood, rain, snow, seismic and wind vary based on the location of the building site. The following table gives the IBC section and ASCE/SEI 7 chapter for various types of load.

    REFERENCED IBC SECTIONS AND ASCE/SEI 7 CHAPTERS FOR LOADS
    TYPE OF LOADIBC SECTIONASCE/SEI 7 CHAPTER
    1. Section 1612 references ASCE 24 which references Chapter 5 of ASCE/SEI 7
    Dead loadsSection 1606Chapter 3
    Live loadsSection 1607, Table 1607.1Chapter 4
    Snow loadsSection 1608Chapter 7
    Wind loadsSection 1609Chapter 6
    Soil lateral loadsSection 1610Chapter 3
    Rain loadsSection 1611Chapter 8
    Flood loadsSection 1612Chapter 51
    Earthquake loadsSection 1613Chapter 11-22
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  2. Structural Materials.
    The structural design begins with the selection of the type of structural materials to be used to support the building. Structural framing systems are constructed of concrete, masonry, steel or wood. Some miscellaneous or specialty structures and components, such as awnings, canopies and cladding, are often constructed of aluminum.
    The design of various structural materials is covered in specific material chapters in the code which in turn reference design standards for the type of material involved. The referenced standards in the 2009 IBC for the structural materials are shown in the following table:
    STRUCTURAL DESIGN STANDARDS FOR STRUCTURAL MATERIALS1
    MATERIALIBC/CBC CHAPTERREFERENCED STANDARD
    1. The above table shows the main structural design standards for these structural materials. For a complete list of referenced standards, see IBC Chapter 35.
    Concrete19ACI 318—08
    Building Code Requirements for Structural Concrete
    Aluminum20ADM 1—05
    Aluminum Design Manual
    Masonry21TMS 402-08/ACI 530-08/ASCE 5-08
    Building Code Requirements and Specification for Masonry Structures (MSJC Code)
    Steel22AISC 360—05
    Specification for Structural Steel Buildings
    AISC 341—05
    Seismic Provisions for Structural Steel Buildings, including Supplement No. 1 dated 2006
    AISI S100—2007
    North American Specification for the Design of Cold-Formed Steel Structural Members
    Wood23AF&PA NDS—05
    National Design Specification (NDS) for Wood Construction with 2005 Supplement
    AF&PA SDPWS—08
    Special Design Provisions for Wind and Seismic
  3. Structural Analysis, Design and Detailing.
    Once the applicable loads are determined, the structural system of the building must be analyzed to determine the effects of the governing gravity and lateral loads that act on the structure. The structural system of a typical building consists of the roof and floor systems, walls, beams and columns, and the foundation. From the structural analysis, the next step is to design the structural members, elements and systems to provide the minimum level of resistance in accordance with the various load combinations prescribed in Section 1605.
    Once the structural elements and systems are designed, the next step is to detail the load transfer connections to provide a complete load path from the point of origin to the resisting element. In general, the ultimate resisting element of buildings and structures is the foundation and supporting ground. The final step is to prepare a complete set of construction documents as required by Sections 107 and 1603. Construction documents are defined in Section 202 as “Written, graphic and pictorial documents prepared or assembled for describing the design, location and physical characteristics of the elements of a project necessary for obtaining a building permit.” In general, construction documents consist of plans, specifications and calculations.
    Section 1603.1 requires construction documents to show the size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. Design loads required by Sections 1603.1.1 through 1603.1.9 must be indicated on the construction documents. If complete construction documents consisting of plans, specifications and calculations are provided, the items listed in Sections 1603.1.1 through 1603.9 are generally included.
    x The exception permits construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 need only indicate the following:
    Floor and roof live loads
    Ground snow load, Pg.
    Basic (3-second gust) wind speed (mph) and wind exposure category.
    Seismic design category and site class.
    Flood design data where sited in flood hazard areas
    Design load-bearing values of soils.

General Requirements

  1. Occupancy Category (IBC/CBC Table 1604.5).
    Determine the occupancy category of the building based on Table 1604.5.
    Where a structure is occupied by two or more occupancies that are not the same occupancy category, the building must be classified in the highest occupancy category corresponding to the various occupancies.
    Where structures have two or more portions that are structurally separated, each separate portion should be separately classified.
    Where a separated portion of a structure provides required access or egress from another portion of the building with a higher occupancy category, both portions of the building must be assigned the higher occupancy category.
    Where a separated portion of a structure shares life safety components with another portion of the building with a higher occupancy category, both portions of the building must be assigned the higher occupancy category.
  2. Floor and roof live loads (IBC/CBC Table 1607.1).

    Determine uniformly distributed and concentrated floor live load for the floor areas of the building in accordance with Section 1603.1.1 and Table 1607.1.
    Floor live load reduction in accordance with Section 1607.9 should be indicated for each type of live load that is reduced.
    Determine the roof live load for roof areas in accordance with Section 1607.11.
    Roof live load reduction in accordance with Section 1607.11.2 should be indicated for roof live loads that are reduced.

  3. Snow load (IBC/CBC Section 1608, ASCE/SEI 7 Section 7).

    Determine the ground snow load, Pg, based on the location of the building site in accordance with Figure 1608.2 for the continuous United States and Table 1608.2 for Alaska.
    In areas where the ground snow load, Pg, exceeds 10 psf, the following information should be determined:

    1. Flat-roof snow load, Pf.
    2. Snow exposure factor, Ce.
    3. Snow load importance factor, I.
    4. Thermal factor, Cr.
  4. Wind speed and wind exposure category.
    Determine the following information related to wind loads in accordance with Section 1603.1.4:
    1. Basic 3-second gust wind speed (mph).
    2. Wind importance factor, I.
    3. Wind exposure category (B, C, D). If more than one wind exposure is used, the wind exposure for each wind direction should be determined.
    4. The applicable internal pressure coefficient.
    5. The design wind pressure (psf) used for the design of exterior component and cladding materials not specifically designed by the registered design professional should be indicated. xi
  5. Earthquake design requirements.
    Determine the following information related to seismic loads regardless of whether seismic loads govern the design of the lateral-force-resisting system of the building:
    1. Seismic importance factor, I, based on occupancy category.
    2. Mapped spectral response accelerations, SS and SI.
    3. Site class.
    4. Design spectral response coefficients, SDS and SDI.
    5. Seismic design category.
    6. Basic seismic-force-resisting system(s).
    7. Design base shear.
    8. Seismic response coefficient(s), CS.
    9. Response modification factor(s), R.
    10. Analysis procedure used.
  6. Geotechnical information.
    The design load bearing values of soils shall be shown on the construction documents in accordance with Section 1603.1.6.
  7. Special loads.
    Determine any special loads that are applicable to the design of the building, structure or portions thereof along with the specific section of the code that addresses the special loading condition in accordance with Section 1603.1.8.
  8. Load combinations.
    Buildings and other structures and portions thereof are required to be designed to resist the load combinations specified in Section 1605.2 or 1605.3 and Chapters 18 through 23, and the special seismic load combinations with overstrength as required by Section 1605.1 and ASCE/SEI 7.
  9. Wind and seismic detailing.
    Lateral-force-resisting systems are required to conform to the seismic detailing requirements of the code and ASCE/SEI 7 (excluding Chapter 14 and Appendix 11A) even when wind load effects are greater than seismic load effects. See Section 1604.10.
  10. Serviceability.
    Structural systems and members shall be designed to have adequate stiffness to limit deflections and lateral drift. The deflection of structural members shall not exceed the more restrictive of the limitations of Sections 1604.3.2 through 1604.3.6 or that permitted by Table 1604.3. Structural systems shall be designed to have adequate stiffness to limit deformation and lateral drift due to earthquake loading in accordance with Section 12.12.1 of ASCE/SEI 7.
  11. Foundation.
    A foundation system must be designed that provides adequate support for gravity and lateral loads. Walls of buildings of conventional light frame construction, as defined in Section 202, are permitted to be supported by footings constructed in accordance with Table 1809.7. Otherwise, the foundation system must be designed in accordance with other provisions of Chapter 18. The following table gives a summary of applicable sections for foundation systems.
    FOUNDATION REQUIREMENTS
    SUBJECTIBC SECTION
    Presumptive load-bearing values of soils1806, Table 1806.2
    Foundation walls, retaining walls and embedded posts & poles1807
    General requirements for foundations1808
    Minimum concrete specified concrete strengthTable 1808.8.1
    Minimum concrete coverTable 1808.8.2
    Shallow foundations (footings)1809
    Prescriptive footings for light frame wallsTable 1809.7
    Deep foundations1810
    xii
    A geotechnical investigation is required where required by Section 1803.2 unless the building official determines that a soils investigation is not required in accordance with the exception. A geotechnical investigation is required for buildings assigned to Seismic Design Categories C, D, E and F in accordance with Sections 1803.5.11 and 1803.5.12.
  12. Excavation, grading and fill
    Requirements for excavation, grading and fill related to foundation construction are covered in Section 1804. General requirements for site grading are covered in Appendix J.
  13. Flood design data.
    Where required by Section 1612.5, buildings located in flood hazard areas as established in Section 1612.3 are required to provide documentation that includes the following information regardless of whether flood loads govern the design of the building:
    1. In flood hazard areas not subject to high-velocity wave action, the elevation of the proposed lowest floor, including the basement; and the elevation to which any nonresidential building will be dry flood proofed.
    2. In flood hazard areas not subject to high-velocity wave action, the elevation to which any nonresidential building will be dry floodproofed.
    3. In flood hazard areas subject to high-velocity wave action, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.
  14. Special inspection.
    Where special inspection, special inspection for seismic resistance, or structural testing for seismic resistance is required by Section 1704, 1707 or 1708, the registered design professional in responsible charge is required to prepare a statement of special inspections in accordance with Section 1705. The statement of special inspections must be submitted by the permit applicant as a condition of permit issuance in accordance with Section 106.1.
    A statement of special inspections is not required for structures designed and constructed in accordance with the conventional construction provisions of Section 2308 unless specific components in the structure require special inspection.
    The statement of special inspections is permitted to be prepared by a qualified person approved by the building official for construction not designed by a registered design professional.
    SPECIAL INSPECTION REQUIREMENTS
    TYPE OF SPECIAL INSPECTIONAPPLICABLE SECTIONREQUIRED VERIFICATION AND INSPECTION
    Where required by the provisions of Section 1709.2 or 1709.3, the owner shall employ a registered design professional to perform structural observations as defined in Section 1702. At the conclusion of the work included in the permit, the structural observer shall submit a written statement to the building official that identifies any reported deficiencies that have not been resolved.
    Steel construction1704.3Table 1704.3
    Concrete construction1704.4Table 1704.4
    Masonry construction1704.5 
    Level 1Table 1704.5.1
    Level 2Table 1704.5.3
    Wood construction1704.6—
    Soils1704.7Table 1704.7
    Driven deep foundations1704.8Table 1704.8
    Cast in place deep foundations1704.9Table 1704.9
    Helical pile foundations1704.10—
    Vertical masonry foundations1704.11—
    1704.5
    Sprayed fire resistant materials1704.12—
    Mastic and intumescent fire resistive coatings1704.13—
    Exterior insulation and finish (EIFS) systems1704.14—
    Special cases1704.15—
    Smoke control systems1704.16—
    xiii
  15. Special inspection for wind and seismic resistance.
    Section 1706.1 requires special inspections for wind requirements based on wind speed and exposure category as prescribed in Section 1706.2 through 1706.4, unless exempted by the exceptions to Section 1704.1.
    Section 1707.1 requires special inspections for seismic resistance based on seismic design category as prescribed in Sections 1707.2 through 1707.9, unless exempted by the exceptions of Section 1704.1 or 1705.3.
  16. Structural testing for seismic resistance.
    Section 1708.1 requires specific testing and qualification for seismic resistance as prescribed in Sections 1708.2 through 1708.5, unless exempted from special inspections by the exceptions of Section 1704.1 and 1705.3.
  17. Structural observation.
    Where required by the provisions of Section 1710.2 or 1710.3 the owner is required to employ a registered design professional to perform structural observations as defined in Section 1702. Section 1710.2 requires structural observations for seismic resistance for certain structures assigned to Seismic Design Category D, E or F; Section 1710.3 requires structural observations for wind requirements for certain structures sited where the wind speed exceeds 110 mph.
    At the conclusion of the work included in the permit, the structural observer is required to submit a written statement to the building official that identifies any reported deficiencies that have not been resolved.
    Prior to the commencement of observations, the structural observer is required to submit a written statement to the building official identifying the structural observations.
    At the conclusion of the work included in the permit, the structural observer is required to submit a written statement to the building official indicating what site visits have been made, identifies any deficiencies that have not been resolved.
  18. Contractor responsibility.
    Section 1709 requires each contractor responsible for the construction of a main wind-or seismic-force-resisting system, designated seismic system or a wind-or seismic-resisting component listed in the statement of special inspections is required to submit a written statement of responsibility to the building official and the owner prior to the commencement of work on the system or component. (The term “designated seismic system” is defined in Section 1702 and Section 11.2 of ASCE⁄SEI7). The contractor's statement of responsibility is required to acknowledge awareness of the special requirements contained in the statement of special inspections.
  19. Phased approvals.
    Construction of foundations or other part of a building is permitted before the construction documents for the whole building or structure have been submitted, provided adequate information has been filed. The holder of such permit for the foundation or other part of a building proceeds at their own risk and without assurance that a permit for the entire structure will be granted.
  20. Amended construction documents.
    Work must be constructed in accordance with the approved construction documents and any changes made during construction that are not in compliance with the approved construction documents must be resubmitted for approval as amended construction documents.
  21. Deferred submittals.
    Deferred submittals are items that are not submitted at the time of permit application and must have the prior approval of the building official in accordance with Section 107.3.4.2. The registered design professional in responsible charge is required to list the deferred submittals on the construction documents for review by the building official. Documents for deferred submittal items must be reviewed by the registered design professional in responsible charge who will forward them to the building official with a notation indicating that they have been reviewed and are in general conformance with the design of the building.
xiv

How to Distinguish Between Model Code Language and California Amendments

To distinguish between model code language and the incorporated California amendments, including exclusive California standards. California amendments will appear in italics.

[BSC] This symbol within a section identifies which State agency(s), by its “acronym,” has amended a section of the model code.

Legend of Acronyms of Adopting State Agencies
BSCCalifornia Building Standards Commission
SFMOffice of the State Fire Marshal
HCDDepartment of Housing and Community Development
DSA-ACDivision of the State Architect-Access Compliance
DSA-SSDivision of the State Architect-Structural Safety
DSA-SS⁄CCDivision of the State Architect-Structural Safety⁄Community Colleges
OSHPDOffice of Statewide Health Planning and Development
CSACorrections Standards Authority
DPHDepartment of Public Health
AGRDepartment of Food and Agriculture
CECCalifornia Energy Commission
CADepartment of Consumer Affairs:
Board of Barbering and Cosmetology
Board of Examiners in Veterinary Medicine
Board of Pharmacy
Acupuncture Board
Bureau of Home Furnishings
Structural Pest Control Board
SLState Librarian
SLCState Lands Commission
DWRDepartment of Water Resources

Symbols in the margins indicate the status of code changes as follows:

This symbol indicates that a change has been made to a California amendment.

This symbol indicates California deletion of California language.

xv xvi

California Matrix Adoption Tables

Format of the California Matrix Adoption Tables

The matrix adoption tables, which follow, show the user which state agencies have adopted and⁄or amended given sections of the model code. The building application determines which state agency's adoptions apply. See Section's 102 through 114 for building applications and enforcement responsibilities.

Agencies are grouped together, based on either local or state enforcement responsibilities. For example, regulations from SFM are enforced both at the state and local levels; therefore, SFM is listed twice in each adoption table indicating state enforcement responsibilities and local enforcement responsibilities.

The side headings identify the scope of state agencies' adoption as follows:

Adopt the entire IBC chapter without state amendments.

If there is an “X” under a particular state agency's acronym on this row; this means that particular state agency has adopted the entire model code chapter without any state amendments.

Example:

CHAPTER 2 – DEFINITIONS AND ABBREVIATIONS
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCASLSLC
121-ACACSSSS⁄CC1234
Adopt entire chapter X                 
Adopt entire chapter as amended (amended sections listed below)     SAMPLE        
Adopt only those sections that are listed below                   
Chapter⁄Section                   

Adopt the entire IBC chapter as amended, state-amended sections are listed below:

If there is an “X” under a particular state agency's acronym on this row, it means that particular state agency has adopted the entire model code chapter; with state amendments.

Each state-amended section that the agency has added to that particular chapter is listed. There will be an “X” in the column, by that particular section, under the agency's acronym, as well as an “X” by each section that the agency has adopted.

Example:

CHAPTER 2 – DEFINITIONS AND ABBREVIATIONS
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCASLSLC
121-ACACSSSS⁄CC1234
Adopt entire chapter                   
Adopt entire chapter as amended (amended sections listed below) X                 
Adopt only those sections that are listed below     SAMPLE        
Chapter⁄Section                   
202 X                 
xvii

Adopt only those sections that are listed below:

If there is an “X” under a particular state agency's acronym on this row, it means that particular state agency is adopting only specific model code or state-amended sections within this chapter. There will be an “X” in the column under the agency's acronym, as well as an “X” by each section that the agency has adopted.

Example:

CHAPTER 2-DEFINITIONS AND ABBREVIATIONS
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCASLSLC
121-ACACSSSS⁄CC1234
Adopt entire chapter                   
Adopt entire chapter as amended (amended sections listed below)                   
Adopt only those sections that are listed below   XX SAMPLE       
Chapter 1                   
202   XX SAMPLE       
202   XX  CONT        
203   XX              
203   XX              
xviii

ORDINANCE

The International Codes are designed and promulgated to be adopted by reference by ordinance. Jurisdictions wishing to adopt the 2010 California Building Code as an enforceable regulation governing structures and premises should ensure that certain factual information is included in the adopting ordinance at the time adoption is being considered by the appropriate governmental body. The following sample adoption ordinance addresses several key elements of a code adoption ordinance, including the information required for insertion into the code text.

SAMPLE ORDINANCE FOR ADOPTION OF THE CALIFORNIA BUILDING CODE ORDINANCE NO.______

An ordinance of the [JURISDICTION] adopting the 2010 edition of the California Building Code, regulating and governing the conditions and maintenance of all property, buildings and structures; by providing the standards for supplied utilities and facilities and other physical things and conditions essential to ensure that structures are safe, sanitary and fit for occupation and use; and the condemnation of buildings and structures unfit for human occupancy and use and the demolition of such structures in the [JURISDICTION]; providing for the issuance of permits and collection of fees therefor; repealing Ordinance No.______ of the [JURISDICTION] and all other ordinances and parts of the ordinances in conflict therewith.

The [GOVERNING BODY] of the [JURISDICTION] does ordain as follows:

Section 1. That a certain document, three (3) copies of which are on file in the office of the [TITLE OF JURISDICTION'S KEEPER OF RECORDS] of [NAME OF JURISDICTION], being marked and designated as the California Building Code, 2010 edition, including Appendix Chapters [FILL IN THE APPENDIX CHAPTERS BEING ADOPTED] (see California Building Code Section 101.2.3, 2010 edition), as published by the International Code Council, be and is hereby adopted as the Building Code of the [JURISDICTION], in the State of California for regulating and governing the conditions and maintenance of all property, buildings and structures; by providing the standards for supplied utilities and facilities and other physical things and conditions essential to ensure that structures are safe, sanitary and fit for occupation and use; and the condemnation of buildings and structures unfit for human occupancy and use and the demolition of such structures as herein provided; providing for the issuance of permits and collection of fees therefor; and each and all of the regulations, provisions, penalties, conditions and terms of said Building Code on file in the office of the [JURISDICTION] are hereby referred to, adopted, and made a part hereof, as if fully set out in this ordinance, with the additions, insertions, deletions and changes, if any, prescribed in Section 2 of this ordinance.

Section 2. The following sections are hereby revised:

Section 101.1. Insert: [NAME OF JURISDICTION]

Section 1612.3. Insert: [NAME OF JURISDICTION]

Section 1612.3. Insert: [DATE OF ISSUANCE]

Section 3412.2. Insert: [DATE IN ONE LOCATION]

Section 3. That Ordinance No.______ of [JURISDICTION] entitled [FILL IN HERE THE COMPLETE TITLE OF THE ORDINANCE OR ORDINANCES IN EFFECT AT THE PRESENT TIME SO THAT THEY WILL BE REPEALED BY DEFINITE MENTION] and all other ordinances or parts of ordinance in conflict herewith are hereby repealed.

Section 4. That if any section, subsection, sentence, clause or phrase of this ordinance is, for any reason, held to be unconstitutional, such decision shall not affect the validity of the remaining portions of this ordinance. The [GOVERNING BODY] hereby declares that it would have passed this ordinance, and each section, subsection, clause or phrase thereof, irrespective of the fact that any one or more sections, subsections, sentences, clauses and phrases be declared unconstitutional.

Section 5. That nothing in this ordinance or in the Building Code hereby adopted shall be construed to affect any suit or proceeding impending in any court, or any rights acquired, or liability incurred, or any cause or causes of action acquired or existing, under any act or ordinance hereby repealed as cited in Section 3 of this ordinance; nor shall any just or legal right or remedy of any character be lost, impaired or affected by this ordinance.

Section 6. That the [JURISDICTION'S KEEPER OF RECORDS] is hereby ordered and directed to cause this ordinance to be published. (An additional provision may be required to direct the number of times the ordinance is to be published and to specify that it is to be in a newspaper in general circulation. Posting may also be required.)

Section 7. That this ordinance and the rules, regulations, provisions, requirements, orders and matters established and adopted hereby shall take effect and be in full force and effect [TIME PERIOD] from and after the date of its final passage and adoption.

xix xx

TABLE OF CONTENTS

VOLUME 1
CHAPTER 1 SCOPE AND ADMINISTRATION3
DIVISION I CALIFORNIA ADMINISTRATION3
Section
1.1General3
1.2Building Standards Commission5
1.3Corrections Standards Authority6
1.4Department of Consumer Affairs6
1.5Reserved7
1.6Department of Food and Agriculture7
1.7California Department of Public Health7
1.8Department of Housing and Community Development7
1.8.2Authority and Abbreviations7
1.8.3Local Enforcing Agency8
1.8.4Permits, Fees, Applications and Inspections9
1.8.5Right-of-Entry for Enforcement10
1.8.6Local Modification by Ordinance or Regulation10
1.8.7Alternate Materials, Designs, Tests and Methods of Construction10
1.8.8Appeals Board11
1.8.9Unsafe Buildings or Structures12
1.8.10Other Building Regulations12
1.9Division of the State Architect12
1.10Office of Statewide Health Planning and Development15
1.11Office of the State Fire Marshal16
1.12State Librarian20
1.13Reserved20
1.14California State Lands Commission20
DIVISION II SCOPE AND ADMINISTRATION21
101General21
102Applicability21
103Department of Building Safety22
104Duties and Powers of Building Officials22
105Permits23
106Floor and Roof Design Loads25
107Submittal Documents25
108Temporary Structures and Uses27
109Fees27
110Inspections27
111Certificate of Occupancy28
112Service Utilities29
113Board of Appeals29
114Violations29
115Stop Work Order29
116Unsafe Structures and Equipment29
CHAPTER 2 DEFINITIONS39
Section
201General39
202Definitions39
CHAPTER 3 USE AND OCCUPANCY CLASSIFICATION59
Section
301General59
302Classification59
303Assembly Group A59
304Business Group B60
305Educational Group E60
306Factory Group F61
307High-Hazard Group H61
308Institutional Group I70
309Mercantile Group M71
310Residential Group R71
311Storage Group S74
312Utility and Miscellaneous Group U75
313Laboratories Group L [SFM]75
CHAPTER 4 SPECIAL DETAILED REQUIREMENTS BASED ON USE AND OCCUPANCY81
Section
401Scope81
402Covered Mall and Open Mall Buildings81
403High-Rise Buildings and Group I-2 Occupancies Having Occupied Floors Located more than 75 Feet Above the Lowest Level of Fire Department Vehicle Access84
404Atriums88
405Underground Buildings88
406Motor-Vehicle-Related Occupancies89
407Group I-293
408Group I-396
409Motion Picture Projection Rooms99
410Stages and Platforms100
411Special Amusement Buildings101
412Aircraft-Related Occupancies102
413Combustible Storage105
414Hazardous Materials105
415Groups H-1, H-2, H-3, H-4 and H-5109
416Application of Flammable Finishes122
417Drying Rooms122
418Organic Coatings122
419Live⁄Work Units123
420Groups R-1, R-2, R-2.1, R-3, R-3.1 and R-4123
421Hydrogen Cutoff Rooms124
422Ambulatory Health Care Facilities125
423Storm Shelters125
424Special Provisions for Residential Hotels [HCD 1& HCD 1-AC]125
425Special Provisions for Licensed 24-Hour Care Facilities in a Group R-2.1, R-3.1, R-4 [SFM]125
426Group I-4 [SFM]128
427Reserved129
428Reserved129
429Reserved129
430Horse Racing Stables [SFM]129
431Pet Kennels [SFM]129
432Combustion Engines and Gas Turbines [SFM]129
433Fixed Guideway Transit Systems [SFM]130
434Explosives [SFM]133
435Reserved136
436Winery Caves [SFM]136
437Reserved137
438Reserved137
439Public Libraries [SL AND SFM]137
440Group C [SFM]138
441Reserved140
442Group E [SFM]140
443Group L [SFM]141
444Reserved144
445Large Family Day-Care Homes [SFM]144
CHAPTER 5 GENERAL BUILDING HEIGHTS AND AREAS149
Section
501General149
502Definitions149
503General Building Height and Area Limitations149
504Building Height149
505Mezzanines151
506Building Area Modifications152
507Unlimited Area Buildings153
508Mixed Use and Occupancy154
509Special Provisions156
CHAPTER 6 TYPES OF CONSTRUCTION163
Section
601General163
602Construction Classification163
603Combustible Material in Type I and II Construction165
CHAPTER 7 FIRE AND SMOKE PROTECTION FEATURES169
Section
701General169
702Definitions169
703Fire-Resistance Ratings and Fire Tests170
704Fire-Resistance Rating of Structural Members171
705Exterior Walls173
706Fire Walls177
707Fire Barriers179
708Shaft Enclosures180
709Fire Partitions184
710Smoke Barriers185
711Smoke Partitions185
712Horizontal Assemblies186
713Penetrations187
714Fire-Resistant Joint Systems189
715Opening Protectives190
716Ducts and Air Transfer Openings194
717Concealed Spaces199
718Fire-Resistance Requirements for Plaster201
719Thermal-and Sound-Insulating Materials201
720Prescriptive Fire Resistance202
721Calculated Fire Resistance224
CHAPTER 7A MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR WILDFIRE EXPOSURE255
Section
701AScope, Purpose and Application255
702ADefinitions256
703AStandards of Quality256
704AIgnition-Resistant Construction257
705ARoofing258
706AVents258
707AExterior Covering258
708AExterior Windows and Doors260
709ADecking260
710AAccessory Structures261
CHAPTER 8 INTERIOR FINISHES265
Section
801General265
802Definitions265
803Wall and Celling Finishes265
804Interior Floor Finish268
805Combustible Materials in Type I and II Construction268
806Decorative Materials and Trim269
807Insulation269
808Acoustical Ceiling Systems269
CHAPTER 9 FIRE PROTECTION SYSTEMS277
Section
901General277
902Definitions277
903Automatic Sprinkler Systems280
904Alternative Automatic Fire-Extinguishing Systems287
905Standpipe Systems289
906Portable Fire Extinguishers292
907Fire Alarm and Detection Systems294
908Emergency Alarm Systems308
909Smoke Control Systems308
910Smoke and Heat Vents315
911Fire Command Center317
912Fire Department Connections318
913Fire Pumps318
914Emergency Responder Safety Features319
915Emergency Responder Radio Coverage319
CHAPTER 10 MEANS OF EGRESS325
Section
1001Administration325
1002Definitions325
1003General Means of Egress326
1004Occupant Load329
1005Egress Width330
1006Means of Egress Illumination330
1007Accessible Means of Egress331
1008Doors, Gates and Turnstiles334
1009Stairways340
1010Ramps343
1011Exit Signs344
1012Handrails346
1013Guards347
1014Exit Access348
1015Exit and Exit Access Doorways349
1016Exit Access Travel Distance351
1017Aisles352
1018Corridors352
1019Egress Balconies354
1020Exits354
1021Number of Exits and Continuity354
1022Exit Enclosures355
1023Exit Passageways357
1024Luminous Egress Path Markings357
1025Horizontal Exits359
1026Exterior Exit Ramps and Stairways360
1027Exit Discharge360
1028Assembly361
1029Emergency Escape and Rescue366
CHAPTER 11 RESERVED369
CHAPTER 11A HOUSING ACCESSIBILITY373
Section
1101AApplication373
1102ABuilding Accessibility373
1103ADesign and Construction374
1104ACovered Multifamily Dwellings374
1105AGarages, Carports and Parking Facilities375
1106ASite and Building Characteristics375
1107ADefinitions375
1108AGeneral Requirements for Accessible Parking and Exterior Routes of Travel378
1109AParking Facilities378
1110AExterior Routes of Travel380
1111AChanges in Level on Accessible Routes380
1112ACurb Ramps on Accessible Routes381
1113AWalks and Sidewalks on an Accessible Route381
1114AExterior Ramps and Landings on Accessible Routes382
1115AExterior Stairways383
1116AHazards on Accessible Routes384
1117AGeneral Requirements for Accessible Entrances, Exits, Interior Routes of Travel and Facility Accessibility385
1118AEgress and Areas of Refuge385
1119AInterior Routes of Travel385
1120AInterior Accessible Routes385
1121AChanges in Level on Accessible Routes386
1122AInterior Ramps and Landings on Accessible Routes386
1123AInterior Stairways387
1124AElevators and Platform (Wheelchair) Lifts388
1125AHazards on Accessible Routes390
1126ADoors390
1127ACommon Use Facilities391
1128ACovered Dwelling Units398
1129AReserved398
1130AAccessible Route Within Covered Multifamily Dwelling Units398
1131AChanges in Level on Accessible Routes398
1132ADoors398
1133AKitchens400
1134ABathing and Toilet Facilities400
1135ALaundry Rooms403
1136AElectrical Receptacle, Switch and Control Heights403
1137AOther Features and Facilities405
1138AReserved405
1139AAccessible Drinking Fountains405
1140AAccessible Telephones405
1141AAccessible Swimming Pools406
1142AElectrical Receptacle, Switch and Control Heights407
1143ASignage407
1144AReserved408
1145AReserved408
1146AReserved408
1147AReserved408
1148AReserved408
1149AReserved408
1150ASite Impracticality Tests409
CHAPTER 11B ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMODATIONS, COMMERCIAL BUILDINGS AND PUBLICLY FUNDED HOUSING465
Section
1101BScope465
1102BDefinitions465
1103BBuilding Accessibility468
1104BAccessibility for Group A Occupancies469
1105BAccessibility for Group B Occupancies472
1106BAccessibility for Group E Occupancies473
1107BFactories and Warehouses474
1108BAccessibility for Group H Occupancies474
1109BAccessibility for Group I Occupancies475
1110BAccessibility for Group M Occupancies475
1111BAccessibility for Group R Occupancies477
1112BReserved479
1113BReserved479
1114BFacility Accessibility479
1115BBathing and Toilet Facilities (Sanitary Facilities)480
1116BElevators and Special Access (Wheelchair) Lifts486
1117BOther Building Components489
1118BSpace Allowance and Reach Ranges497
1119BSpecial Standards of Accessibility for Buildings with Historical Significance497
1120BFloor and Levels497
1121BTransportation Facilities498
1122BFixed or Built-in Seating, Tables and Counters501
1123BAccess to Employee Areas502
1124BGround and Floor Surfaces502
1125BStorage502
1126BVending Machines and Other Equipment502
1127BExterior Routes of Travel503
1128BPedestrian Grade Separations (Overpasses and Underpasses)504
1129BAccessible Parking Required504
1130BParking Structures506
1131BPassenger Drop-off and Loading Zones506
1132BOutdoor Occupancies506
1133BGeneral Accessibility for Entrances, Exits and Paths of Travel508
1134BAccessibility for Existing Buildings515
1135BHistoric Preservation—Special Standards of Accessibility for Buildings with Historical Significance516
CHAPTER 11C STANDARDS FOR CARD READERS AT GASOLINE FUEL-DISPENSING FACILITIES587
Section
1101CCard-Reader Devices at Fuel-Dispensing Equipment587
1102CApplication587
1103CNumber of Accessible Card-Reading Devices Required587
1104CRequired Features587
CHAPTER 12 INTERIOR ENVIRONMENT593
Section
1201General593
1202Definitions593
1203Ventilation593
1204Temperature Control594
1205Lighting595
1206Yards or Courts595
1207Sound Transmission596
1208Interior Space Dimensions598
1209Access to Unoccupied Spaces599
1210Surrounding Materials599
1211Garage Door Springs599
1212Reserved600
1213Reserved600
1214Reserved600
1215Reserved600
1216Reserved600
1217Reserved600
1218Reserved600
1219Reserved600
1220Reserved600
1221Reserved600
1222Reserved600
1223Reserved600
1224Hospitals600
1225Skilled Nursing and Intermediate-Care Facilities628
1226Clinics633
1227Correctional Treatment Centers636
1228Reserved641
1229Reserved641
1230Minimum Standards for Juvenile Facilities641
1231Local Detention645
1232Reserved651
1233Reserved651
1234Reserved651
1235Sanitary Control of Shellfish (Plants and Operations)651
1236Laboratory Animal Quarters651
1237Wild Animal Quarantine Facilities652
1238Reserved652
1239Reserved652
1240Meat and Poultry Processing Plants652
1241Collection Centers and Facilities654
1242Renderers654
1243Horsemeat and Pet Food Establishments654
1244Reserved655
1245Reserved655
1246Reserved655
1247Reserved655
1248Reserved655
1249Reserved655
1250Pharmacies655
1251Veterinary Facilities655
1252Barber Colleges and Shops656
1253Schools of Cosmetology, Cosmetological Establishments and Satellite Classrooms656
1254Acupuncture Offices657
CHAPTER 13 ENERGY EFFICIENCY659
CHAPTER 14 EXTERIOR WALLS663
Section
1401General663
1402Definitions633
1403Performance Requirements663
1404Materials664
1405Installation of Wall Coverings665
1406Combustible Materials on the Exterior Side of Exterior Walls669
1407Metal Composite Materials (MCM)670
1408Exterior Insulation and Finish Systems (EIFS)671
1409[DSA-SS and DSA-SS/CC, OSHPD 1,2 & 4] Additional Requirements for Anchored and Adhered Veneer671
CHAPTER 15 ROOF ASSEMBLIES AND ROOFTOP STRUCTURES675
Section
1501General675
1502Definitions675
1503Weather Protection675
1504Performance Requirements676
1505Fire Classification677
1506Materials678
1507Requirements for Roof Coverings678
1508Roof Insulation687
1509Rooftop Structures688
1510Reroofing689
1511[DSA-SS and OSHPD 1, 2 & 4] Seismic Anchorage of State Shingle, Clay and Concrete Tile Roof Coverings690
INDEX691
HISTORY NOTE731
VOLUME 2
CHAPTER 16 STRUCTURAL DESIGN5
Section
1601General5
1602Definitions and Notations5
1603Construction Documents6
1604General Design Requirements7
1605Load Combinations10
1606Dead Loads11
1607Live Loads11
1608Snow Loads17
1609Wind Loads20
1610Soil Lateral Loads33
1611Rain Loads34
1612Flood Loads40
1613Earthquake Loads42
1614Structural Integrity48
1615Additional Requirements [DSA-SS/CC]69
CHAPTER 16A STRUCTURAL DESIGN79
Section
1601AGeneral79
1602ADefinitions and Notations79
1603AConstruction Documents81
1604AGeneral Design Requirements82
1605ALoad Combinations84
1606ADead Loads86
1607ALive Loads86
1608ASnow Loads91
1609AWind Loads94
1610ASoil Lateral Loads104
1611ARain Loads104
1612AFlood Loads110
1613AEarthquake Loads112
1614AStructural Integrity117
1615AModifications to ASCE 7119
CHAPTER 17 STRUCTURAL TESTS AND SPECIAL INSPECTIONS129
Section
1701General129
1702Definitions129
1703Approvals129
1704Special Inspections130
1705Statement of Special Inspections141
1706Special Inspections for Wind Requirements143
1707Special Inspections for Seismic Resistance143
1708Structural Testing for Seismic Resistance144
1709Contractor Responsibility145
1710Structural Observations145
1711Design Strengths of Materials145
1712Alternative Test Procedure145
1713Test Safe Load146
1714In-Situ Load Tests146
1715Preconstruction Load Tests146
1716Material and Test Standards147
CHAPTER 17A STRUCTURAL TESTS AND SPECIAL INSPECTIONS151
Section
1701AGeneral151
1702ADefinitions151
1703AApprovals152
1704ASpecial Inspections153
1705AStatement of Special Inspections165
1706ASpecial Inspections for Wind Requirements167
1707ASpecial Inspections for Seismic Resistance167
1708AStructural Testing for Seismic Resistance168
1709AContractor Responsibility169
1710AStructural Observations169
1711ADesign Strengths of Materials169
1712AAlternative Test Procedure170
1713ATest Safe Load170
1714AIn-Situ Load Tests170
1715APreconstruction Load Tests170
1716AMaterial and Test Standards171
CHAPTER 18 SOILS AND FOUNDATIONS175
Section
1801General175
1802Definitions175
1803Geotechnical Investigations175
1804Excavation, Grading and Fill178
1805Dampproofing and Waterproofing179
1806Presumptive Load-Bearing Values of Soils180
1807Foundation Walls, Retaining Walls and Embedded Posts and Poles181
1808Foundations187
1809Shallow Foundations189
1810Deep Foundations192
CHAPTER 18A SOILS AND FOUNDATIONS207
Section
1801AGeneral207
1802ADefinitions207
1803AGeotechnical Investigations208
1804AExcavation, Grading and Fill211
1805ADampproofing and Waterproofing211
1806APresumptive Load-Bearing Values of Soils213
1807AFoundation Walls, Retaining Walls and Embedded Posts and Poles213
1808AFoundations215
1809AShallow Foundations218
1810ADeep Foundations219
1811APrestressed Rock and Soil Foundation Anchors231
CHAPTER 19 CONCRETE235
Section
1901General235
1902Definitions235
1903Specifications for Tests and Materials235
1904Durability Requirements236
1905Concrete Quality, Mixing and Placing236
1906Formwork, Embedded Pipes and Construction Joints238
1907Details of Reinforcement238
1908Modifications to ACI 318239
1909Structural Plain Concrete241
1910Minimum Slab Provisions242
1911Anchorage to Concrete—Allowable Stress Design242
1912Anchorage to Concrete—Strength Design243
1913Shotcrete244
1914Reinforced Gypsum Concrete245
1915Concrete-Filled Pipe Columns245
1916Additional Requirements [DSA-SS/CC]246
CHAPTER 19A CONCRETE253
Section
1902AGeneral253
1902ADefinitions253
1903ASpecifications for Tests and Materials255
1904ADurability Requirements255
1905AConcrete Quality, Mixing and Placing256
1906AFormwork, Embedded Pipes and Construction Joints257
1907ADetails of Reinforcement257
1908AModifications to ACI 318258
1909AStructural Plain Concrete Not Permitted by OSHPD and DSA-SS262
1910AMinimum Slab Provisions262
1911AAnchorage to Concrete— Allowable Stress Design263
1912AAnchorage to Concrete— Strength Design263
1913AShotcrete264
1914AReinforced Gypsum Concrete265
1915AConcrete-Filled Pipe Columns265
1916AConcrete, Reinforcement and Anchor Testing266
1917AExisting Concrete Structures267
CHAPTER 20 ALUMINUM271
Section
2001General271
2002Materials271
2003Inspection271
CHAPTER 21 MASONRY275
Section
2101General275
2102Definitions and Notations275
2103Masonry Construction Materials278
2104Construction280
2105Quality Assurance280
2106Seismic Design281
2107Allowable Stress Design282
2108Strength Design of Masonry282
2109Empirical Design of Masonry282
2110Glass Unit Masonry284
2111Masonry Fireplaces284
2112Masonry Heaters287
2113Masonry Chimneys287
2114Additional Requirements [DSA-SS/CC]291
CHAPTER 21A MASONRY297
Section
2101AGeneral297
2102ADefinitions and Notations298
2103AMasonry Construction Materials301
2104AConstruction302
2105AQuality Assurance305
2106ASeismic Design306
2107AAllowable Stress Design307
2108AStrength Design of Masonry308
2109AEmpirical Design of Masonry Not Permitted by OSHPD and DSA-SS309
2110AGlass Unit Masonry309
2111AMasonry Fireplaces309
2112AMasonry Heaters311
2113AMasonry Chimneys312
2114ANonbearing Walls316
2115AMasonry Screen Walls316
CHAPTER 22 STEEL319
Section
2201General319
2202Definitions319
2203Identification and Protection of Steel for Structural Purposes319
2204Connections319
2205Structural Steel320
2206Steel Joists320
2207Steel Cable Structures321
2208Steel Storage Racks321
2209Cold-Formed Steel321
2210Cold-Formed Steel Light-Frame Construction321
2211Additional Requirements [DSA-SS/CC]322
CHAPTER 22A STEEL327
Section
2201AGeneral327
2202ADefinitions327
2203AIdentification and Protection of Steel for Structural Purposes327
2204AConnections327
2205AStructural Steel328
2206ASteel Joists330
2207ASteel Cable Structures331
2208ASteel Storage Racks331
2209ACold-Formed Steel331
2210ACold-Formed Steel Light-Framed Construction331
2211ALight Modular Steel Moment Frames for Public Elementary and Secondary Schools, and Community Colleges332
2212ATesting333
CHAPTER 23 WOOD337
Section
2301General337
2302Definitions337
2303Minimum Standards and Quality339
2304General Construction Requirements343
2305General Design Requirements for Lateral-Force-Resisting Systems354
2306Allowable Stress Design357
2307Load and Resistance Factor Design358
2308Conventional Light-Frame Construction358
CHAPTER 24 GLASS AND GLAZING411
Section
2401General411
2402Definitions411
2403General Requirements for Glass411
2404Wind, Snow, Seismic and Dead Loads on Glass411
2405Sloped Glazing and Skylights413
2406Safety Glazing415
2407Glass in Handrails and Guards417
2408Glazing in Athletic Facilities417
2409Glass in Elevator Hoistways and Elevator Cars417
CHAPTER 25 GYPSUM BOARD AND PLASTER421
Section
2501General421
2502Definitions421
2503Inspection421
2504Vertical and Horizontal Assemblies421
2505Shear Wall Construction422
2506Gypsum Board Materials422
2507Lathing and Plastering422
2508Gypsum Construction423
2509Gypsum Board in Showers and Water Closets424
2510Lathing and Furring for Cement Plaster (Stucco)424
2511Interior Plaster425
2512Exterior Plaster425
2513Exposed Aggregate Plaster426
CHAPTER 26 PLASTIC431
Section
2601General431
2602Definitions431
2603Foam Plastic Insulation431
2604Interior Finish and Trim434
2605Plastic Veneer435
2606Light-Transmitting Plastics435
2607Light-Transmitting Plastic Wall Panels436
2608Light-Transmitting Plastic Glazing437
2609Light-Transmitting Plastic Roof Panels437
2610Light-Transmitting Plastic Skylight Glazing438
2611Light-Transmitting Plastic Interior Signs439
2612Fiber Reinforced Polymer and Fiberglass-Reinforced Polymer439
2613Reflective Plastic Core Insulation440
CHAPTER 27 ELECTRICAL443
Section
2701General443
2702Emergency and Standby Power Systems443
CHAPTER 28 MECHANICAL SYSTEMS447
Section
2801General447
CHAPTER 29 PLUMBING SYSTEMS449
Section
2901General449
CHAPTER 30 ELEVATORS AND CONVEYING SYSTEMS455
Section
3001General455
3002Hoistway Enclosures455
3003Emergency Operations456
3004Hoistway Venting457
3005Conveying Systems457
3006Machine Rooms458
3007Fire Service Access Elevator458
3008Occupant Evacuation Elevators459
3009Special Requirements for Elevators in Hospitals460
CHAPTER 31 SPECIAL CONSTRUCTION465
Section
3101General465
3102Membrane Structures465
3103Temporary Structures466
3104Pedestrian Walkways and Tunnels466
3105Awnings and Canopies467
3106Marquees468
3107Signs468
3108Telecommunication and Broadcast Towers468
3109Swimming Pool Enclosures and Safety Devices468
3110Automatic Vehicular Gates472
CHAPTER 31A RESERVED473
CHAPTER 31B PUBLIC SWIMMING POOLS477
Section
3101BScope477
3102BDefinitions477
3103BSpecial Pool Classifications478
3104BAccessibility to the Physically Handicapped Person478
3105BAlternate Equipment, Materials and Methods of Construction478
3106BPool Construction478
3107BAdditional Requirements for a Temporary Training Pool479
3108BPool Geometry479
3109BPermanent Markings479
3110BSteps, Recessed Steps, Ladders and Recessed Stairs (Treads)482
3111BHandholds483
3112BDiving Boards483
3113BPool Decks483
3114BPool Lighting483
3115BBathhouse Dressing, Shower and Toilet Facilities484
3116BDrinking Fountains484
3117BHose Bibbs484
3118BEnclosure of Pool Area484
3119BSigns485
3120BIndoor Pool Ventilation487
3121BFoundations For Pool Equipment487
3122BGas Chlorination Equipment Room487
3123BGeneral Requirements487
3124BTurnover Time487
3125BRecirculation Piping System and Components487
3126BRecirculation Pump Capacity488
3127BWater Supply Inlets488
3128BFilters (All Types)488
3129BRapid Sand Pressure Filters488
3130BDiatomaceous Earth Filters489
3131BHigh-Rate Sand Filters489
3132BChemical Feeders489
3133BDisinfectant Feeders489
3134BPool Fittings490
3135BSpa Pool Special Requirements491
3136BCleaning Systems491
3137BWaste Water Disposal491
3138BReserved491
3139BReserved491
3140BReserved491
3141BReserved491
3142BReserved491
3143BReserved491
3144BReserved491
3145BReserved491
3146BReserved492
3147BReserved492
3148BReserved492
3149BReserved492
3150BReserved492
3151BReserved492
3152BReserved492
3153BReserved492
3154BReserved492
3155BReserved492
3156BReserved492
3157BReserved492
3158BReserved492
3159BReserved492
3160B492
3161B492
3162BAnti-Entrapment Devices and Systems493
CHAPTER 31C RADIATION499
Section
3101CScope499
3102CRadiation Shielding Barriers499
3103CMedical Radiographic and Photofluorographic Installations499
3104CMedical Therapeutic X-Ray Installations499
CHAPTER 31D FOOD ESTABLISHMENTS503
Section
3101DScope503
3102DDefinitions503
3103BBuilding and Structures503
CHAPTER 31E RESERVED505
CHAPTER 31F MARINE OIL TERMINALS509
Section
3101FIntroduction509
3102FAudit and Inspection510
3103FStructural Loading Criteria521
3104FSeismic Analysis and Structural Performance536
3105FMooring and Berthing Analysis and Design543
3106FGeotechnical Hazards and Foundations548
3107FStructural Analysis and Design of Components552
3108FFire Prevention, Detection and Suppression566
3109FPiping and Pipelines570
3110FMechanical and Electrical Equipment573
3111FElectrical Systems576
CHAPTER 32 ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY581
Section
3201General581
3202Encroachments581
CHAPTER 33 SAFEGUARDS DURING CONSTRUCTION585
Section
3301General585
3302Construction Safeguards585
3303Demolition585
3304Site Work585
3305Sanitary585
3306Protection of Pedestrians586
3307Protection of Adjoining Property587
3308Temporary Use of Streets, Alleys and Public Property587
3309Fire Extinguishers587
3310Means of Egress588
3311Standpipes588
3312Automatic Sprinkler System588
CHAPTER 34 EXISTING STRUCTURES591
Section
3401General591
3402Definitions592
3403Additions593
3404Alterations593
3405Repairs594
3406Fire Escapes596
3407Glass Replacement596
3408Change of Occupancy596
3409Historic Buildings597
3410Moved Structures597
3411Accessibility for Existing Buildings597
3412Compliance Alternatives599
3413Existing Group R-1 and Group R-2 Occupancies [SFM]608
3414Existing High-Rise Buildings [SFM]611
3415Existing Group I Occupancies [SFM]613
3416Existing Group L Occupancies [SFM]614
3417Earthquake Evaluation and Design for Retrofit of Existing Buildings614
3418Definitions617
3419Seismic Criteria Selection for Existing Buildings618
3420Method A621
3421Method B621
3422Peer Review Requirements622
3423Additional Requirements for Public Schools and Community Colleges623
CHAPTER 34A EXISTING STRUCTURES627
Section
3401AGeneral627
3402ADefinitions627
3403AAdditions628
3404AAlterations629
3405ARepairs630
3406AFire Escapes631
3407AGlass Replacement631
3408AChange of Occupancy631
3409AHistoric Buildings632
3410AMoved Structures632
3411AAdditions, Alterations, Repairs and Seismic Retrofit to Existing Buildings or Structures Designed in Accordance with Pre-1973 Building Code632
3412ACompliance Alternatives for Additions, Alterations, Repairs and Seismic Retrofit to Existing Structures632
3413AModifications to ASCE 41634
3414APeer Review Requirements636
3415AEarthquake Monitoring Instruments for Existing Buildings637
CHAPTER 35 REFERENCED STANDARDS641
APPENDIX A EMPLOYEE QUALIFICATIONS671
Section
A101Building Official Qualifications671
A102Referenced Standards671
APPENDIX B BOARD OF APPEALS675
Section
B101General675
APPENDIX C GROUP U—AGRICULTURAL BUILDINGS679
Section
C101General679
C102Allowable Height and Area679
C103Mixed Occupancies679
C104Exits679
APPENDIX D FIRE DISTRICTS683
Section
D101General683
D102Building Restrictions683
D103Changes to Buildings684
D104Buildings Located Partially in the Fire District684
D105Exceptions to Restrictions in Fire District684
D106Referenced Standards685
APPENDIX E RESERVED689
APPENDIX F RODENTPROOFING693
Section
F101General693
APPENDIX G FLOOD-RESISTANT CONSTRUCTION697
Section
G101Administration697
G102Applicability697
G103Powers and Duties697
G104Permits698
G105Variances698
G201Definitions699
G301Subdivisions700
G401Site Improvement700
G501Manufactured Homes700
G601Recreational Vehicles700
G701Tanks701
G801Other Building Work701
G901Temporary Structures and Temporary Storage701
G1001Utility and Miscellaneous Group U701
G1101Referenced Standards702
APPENDIX H SIGNS705
Section
H101General705
H102Definitions705
H103Location705
H104Identification705
H105Design and Construction706
H106Electrical706
H107Combustible Materials706
H108Animated Devices706
H109Ground Signs706
H110Roof Signs707
H111Wall Signs707
H112Projecting Signs707
H113Marquee Signs708
H114Portable Signs708
H115Referenced Standards708
APPENDIX I PATIO COVERS711
Section
I101General711
I102Definitions711
I103Exterior Openings711
I104Structural Provisions711
APPENDIX J GRADING715
Section
J101General715
J102Definitions715
J103Permits Required715
J104Permit Application and Submittals715
J105Inspections716
J106Excavations716
J107Fills719
J108Setbacks721
J109Drainage and Terracing721
J110Erosion Control721
J111Referenced Standards721
APPENDIX K GROUP R-3 AND GROUP R-3.1 OCCUPANCIES PROTECTED BY THE FACILITIES OF THE CENTRAL VALLEY FLOOD PROTECTION PLAN723
Section
K101Scope723
K102Definitions723
K103Structural Stability724
K104Evacuation Locations724
K105Space within the Building724
K106Decks and Balconies that are Evacuation Locations724
K107Rooftop Evacuation Locations727
K108Attics that are Evacuation Locations727
K109Alternate Means of Protection727
INDEX729
HISTORY NOTE769
xxxiv
CALIFORNIA BUILDING CODE-MATRIX ADOPTION TABLE
CHAPTER 16–STRUCTURAL DESIGN
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCECCASLSLC
121-ACACSSSS/CC1234
Adopt entire chapter          X         
Adopt entire chapter as amended (amended sections listed below)X XX   X X          
Adopt only those sections that are listed below    XX            X 
Chapter/Section                    
1601.1.1       X            
1601.1.2       X            
1601.1.3       X            
1601.1.4       X            
1601.2       X X          
1601.3       X X          
1602.1         X          
1603.1         X          
1607.1, Table 1607.1         X          
1607.7  XXX               
1607.7.2  XXXX              
1612.3         X          
1613.1         X          
1613.1.1                   X
1613.1.2X                   
1613.3.1X                   
1613.5.1         X          
1613.5.6         X          
1613.5.6.1         X          
1613.5.6.2         X          
1613.6.3X                   
1613.6.9X                   
1615.1.1       X            
1615.1.2       X            
1615.1.3       X            
1615.2.1.1      X            
1615.2.1.2       X            
1615.2.1.3       X            
1615.3.1       X            
1615.4       X            
1615.5.1.1       X            
1615.5.1.2       X            
1615.5.1.3       X            
1615.5.1.4       X            
1615.5.1.5       X            
1615.5.1.6       X             1
Adopt entire chapter          X         
Adopt entire chapter as amended (amended sections listed below)X XX   X X          
Adopt only those sections that are listed below    XX            X 
Chapter/Section                    
1615.5.2       X            
1615.6       X            
1615.7.1       X            
1615.7.2       X            
1615.8       X            
1615.9.1       X            
1615.9.2 - Active Earthquake Fault       X            
1615.9.2 - Base       X            
1615.9.2 - Distance for an Active Earthquake Fault       X            
1615.9.2 - Irregular Structure       X            
1615.9.2 - Next Generation Attenuation (NGA)       X            
1615.9.2 - Structural Elements       X            
1615.9.3       X            
1615.9.4       X            
1615.9.4.1       X            
1615.9.4.2       X            
1615.9.5       X            
1615.9.6       X            
1615.10       X            
1615.10.1       X            
1615.10.2       X            
1615.10.3       X            
1615.10.4       X            
1615.10.5       X            
1615.10.6       X            
1615.10.7       X            
1615.10.8       X            
1615.10.9       X            
1615.10.10       X            
1615.10.11       X            
1615.10.12       X            
1615.10.13       X            
1615.10.14       X            
1615.10.15       X             2
Adopt entire chapter          X         
Adopt entire chapter as amended (amended sections listed below)X XX   X X          
Adopt only those sections that
are listed below		    XX            X 
Chapter/Section                    
1615.10.16       X            
1615.10.17       X            
1615.10.18       X            
1615.10.19       X            
1615.10.20       X            
1615.10.21       X            
1615.10.22       X            
1615.10.23       X            
1615.10.24       X            
1615.10.25       X            
1615.10.26       X            
                     
3 4

CHAPTER 16
STRUCTURAL DESIGN

SECTION 1601
GENERAL

1601.1 Scope. The provisions of this chapter shall govern the structural design of buildings, structures and portions thereof regulated by this code.

1601.1.1 Application. [DSA-SS/CC] The scope of application of Chapter 16 is as follows:

Community college buildings regulated by the Division of the State Architect-Structural Safety/Community Colleges (DSA-SS/CC), as listed in Section 1.9.2.2.

1601.1.2 Identification of amendments. [DSA-SS/CC] Division of the State Architect-Structural Safety/Community Colleges (DSA-SS/CC) amendments appear in this chapter preceded with the appropriate acronym, as follows:

Division of the State Architect-Structural Safety/Community Colleges: [DSA-SS/CC] - For community college building listed in Section 1.9.2.2.

1601.1.3 Reference to other chapters. [DSA-SS/CC] Where reference within this chapter is made to sections in Chapters 17 and 18, the provisions in Chapters 17A and 18A respectively shall apply instead.

1601.1.4 Amendments. [DSA-SS/CC] See Section 1615 for additional requirements.

1601.2 References. [DSA-SS/CC, OSHPD 2] All referenced codes and standards listed in Chapter 35 shall include all the modifications contained in this code to referenced standards. In the event of any discrepancy between this code and a referenced standard, refer to Section 1.1.7.

1601.3 Enforcement agency approval. [DSA-SS/CC, OSHPD 2] In addition to requirements of CCR Title 24, Parts 1 & 2, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the design professional are also subject to approval by the enforcement agency.

SECTION 1602
DEFINITIONS AND NOTATIONS

1602.1 Definitions. The following words and terms shall, for the purposes of this chapter, have the meanings shown herein.

ALLOWABLE STRESS DESIGN. A method of proportioning structural members, such that elastically computed stresses produced in the members by nominal loads do not exceed specified allowable stresses (also called “working stress design”).

DEAD LOADS. The weight of materials of construction incorporated into the building, including but not limited to walls, floors, roofs, ceilings, stairways, built-in partitions, finishes, cladding and other similarly incorporated architectural and structural items, and the weight of fixed service equipment, such as cranes, plumbing stacks and risers, electrical feeders, heating, ventilating and air-conditioning systems and automatic sprinkler systems.

DESIGN STRENGTH. The product of the nominal strength and a resistance factor (or strength reduction factor).

DIAPHRAGM. A horizontal or sloped system acting to transmit lateral forces to the vertical-resisting elements. When the term “diaphragm” is used, it shall include horizontal bracing systems.

Diaphragm, blocked. In light-frame construction, a diaphragm in which all sheathing edges not occurring on a framing member are supported on and fastened to blocking.

Diaphragm boundary. In light-frame construction, a location where shear is transferred into or out of the diaphragm sheathing. Transfer is either to a boundary element or to another force-resisting element.

Diaphragm chord. A diaphragm boundary element perpendicular to the applied load that is assumed to take axial stresses due to the diaphragm moment.

Diaphragm flexible. A diaphragm is flexible for the purpose of distribution of story shear and torsional moment where so indicated in Section 12.3.1 of ASCE 7, as modified in Section 1613.6.1.

Diaphragm, rigid. A diaphragm is rigid for the purpose of distribution of story shear and torsional moment when the lateral deformation of the diaphragm is less than or equal to two times the average story drift.

DURATION OF LOAD. The period of continuous application of a given load, or the aggregate of periods of intermittent applications of the same load.

ENFORCEMENT AGENT. [OSHPD 2] That individual within the agency or organization charged with responsibility for agency or organization compliance with the requirements of this code. Used interchangeably with “Building Official” or “Code Official.”

ESSENTIAL FACILITIES. Buildings and other structures that are intended to remain operational in the event of extreme environmental loading from flood, wind, snow or earthquakes.

FABRIC PARTITION. A partition consisting of a finished surface made of fabric, without a continuous rigid backing, that is directly attached to a framing system in which the vertical framing members are spaced greater than 4 feet (1219 mm) on center.

FACTORED LOAD. The product of a nominal load and a load factor.

GUARD. See Section 1002.1.

5

IMPACT LOAD. The load resulting from moving machinery, elevators, craneways, vehicles and other similar forces and kinetic loads, pressure and possible surcharge from fixed or moving loads.

LIMIT STATE. A condition beyond which a structure or member becomes unfit for service and is judged to be no longer useful for its intended function (serviceability limit state) or to be unsafe (strength limit state).

LIVE LOADS. Those loads produced by the use and occupancy of the building or other structure and do not include construction or environmental loads such as wind load, snow load, rain load, earthquake load, flood load or dead load.

LIVE LOADS (ROOF). Those loads produced (1) during maintenance by workers, equipment and materials; and (2) during the life of the structure by movable objects such as planters and by people.

LOAD AND RESISTANCE FACTOR DESIGN (LRFD). A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term “LRFD” is used in the design of steel and wood structures.

LOAD EFFECTS. Forces and deformations produced in structural members by the applied loads.

LOAD FACTOR. A factor that accounts for deviations of the actual load from the nominal load, for uncertainties in the analysis that transforms the load into a load effect, and for the probability that more than one extreme load will occur simultaneously.

LOADS. Forces or other actions that result from the weight of building materials, occupants and their possessions, environmental effects, differential movement and restrained dimensional changes. Permanent loads are those loads in which variations over time are rare or of small magnitude, such as dead loads. All other loads are variable loads (see also “Nominal loads”).

NOMINAL LOADS. The magnitudes of the loads specified in this chapter (dead, live, soil, wind, snow, rain, flood and earthquake).

OCCUPANCY CATEGORY. A category used to determine structural requirements based on occupancy.

OTHER STRUCTURES. Structures, other than buildings, for which loads are specified in this chapter.

PANEL (PART OF A STRUCTURE). The section of a floor, wall or roof comprised between the supporting frame of two adjacent rows of columns and girders or column bands of floor or roof construction.

RESISTANCE FACTOR. A factor that accounts for deviations of the actual strength from the nominal strength and the manner and consequences of failure (also called “strength reduction factor”).

STRENGTH, NOMINAL. The capacity of a structure or member to resist the effects of loads, as determined by computations using specified material strengths and dimensions and equations derived from accepted principles of structural mechanics or by field tests or laboratory tests of scaled models, allowing for modeling effects and differences between laboratory and field conditions.

STRENGTH, REQUIRED. Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.

STRENGTH DESIGN. A method of proportioning structural members such that the computed forces produced in the members by factored loads do not exceed the member design strength [also called “load and resistance factor design” (LRFD)]. The term “strength design” is used in the design of concrete and masonry structural elements.

VEHICLE BARRIER SYSTEM. A system of building components near open sides of a garage floor or ramp or building walls that act as restraints for vehicles.

NOTATIONS.

D = Dead load.

E = Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4.2 of ASCE 7.

F = Load due to fluids with well-defined pressures and maximum heights.

Fa = Flood load in accordance with Chapter 5 of ASCE 7.

H = Load due to lateral earth pressures, ground water pressure or pressure of bulk materials.

L = Live load, except roof live load, including any permitted live load reduction.

Lr = Roof live load including any permitted live load reduction.

R = Rain load.

S = Snow load.

T = Self-straining force arising from contraction or expansion resulting from temperature change, shrinkage, moisture change, creep in component materials, movement due to differential settlement or combinations thereof.

W = Load due to wind pressure.

SECTION 1603
CONSTRUCTION DOCUMENTS

1603.1 General. Construction documents shall show the size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603.1.1 through 1603.1.9 shall be indicated on the construction documents.

Exception: Construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 shall indicate the following structural design information:

  1. Floor and roof live loads.
  2. Ground snow load, Pg. 6
  3. Basic wind speed (3-second gust), miles per hour (mph) (km/hr) and wind exposure.
  4. Seismic design category and site class.
  5. Flood design data, if located in flood hazard areas established in Section 1612.3.
  6. Design load-bearing values of soils.

[OSHPD 2] Additional requirements are included in Sections 7-115 and 7-125 of the California Administrative Code (Part 1, Title 24, C.C.R).

1603.1.1 Floor live load. The uniformly distributed, concentrated and impact floor live load used in the design shall be indicated for floor areas. Use of live load reduction in accordance with Section 1607.9 shall be indicated for each type of live load used in the design.

1603.1.2 Roof live load. The roof live load used in the design shall be indicated for roof areas (Section 1607.11).

1603.1.3 Roof snow load. The ground snow load, Pg, shall be indicated. In areas where the ground snow load, Pg, exceeds 10 pounds per square foot (psf) (0.479 kN/m2, the following additional information shall also be provided, regardless of whether snow loads govern the design of the roof:

  1. Flat-roof snow load, Pf.
  2. Snow exposure factor, Ce.
  3. Snow load importance factor, I.
  4. Thermal factor, Ct.

1603.1.4 Wind design data. The following information related to wind loads shall be shown, regardless of whether wind loads govern the design of the lateral-force-resisting system of the building:

  1. Basic wind speed (3-second gust), miles per hour (km/hr).
  2. Wind importance factor, I, and occupancy category.
  3. Wind exposure. Where more than one wind exposure is utilized, the wind exposure and applicable wind direction shall be indicated.
  4. The applicable internal pressure coefficient.
  5. Components and cladding. The design wind pressures in terms of psf (kN/m2) to be used for the design of exterior component and cladding materials not specifically designed by the registered design professional.

1603.1.5 Earthquake design data. The following information related to seismic loads shall be shown, regardless of whether seismic loads govern the design of the lateral-force-resisting system of the building:

  1. Seismic importance factor, I, and occupancy category.
  2. Mapped spectral response accelerations, Ss and S1.
  3. Site class.
  4. Spectral response coefficients, SDS and SDl.
  5. Seismic design category.
  6. Basic seismic-force-resisting system(s).
  7. Design base shear.
  8. Seismic response coefficient(S), CS.
  9. Response modification factor(S), R.
  10. Analysis procedure used.

1603.1.6 Geotechnical information. The design loadbearing values of soils shall be shown on the construction documents.

1603.1.7 Flood design data. For buildings located in whole or in part in flood hazard areas as established in Section 1612.3, the documentation pertaining to design, if required in Section 1612.5, shall be included and the following information, referenced to the datum on the community's Flood Insurance Rate Map (FIRM), shall be shown, regardless of whether flood loads govern the design of the building:

  1. In flood hazard areas not subject to high-velocity wave action, the elevation of the proposed lowest floor, including the basement.
  2. In flood hazard areas not subject to high-velocity wave action, the elevation to which any nonresidential building will be dry floodproofed.
  3. In flood hazard areas subject to high-velocity wave action, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.

1603.1.8 Special loads. Special loads that are applicable to the design of the building, structure or portions thereof shall be indicated along with the specified section of this code that addresses the special loading condition.

1603.1.9 Systems and components requiring special inspections for seismic resistance. Construction documents or specifications shall be prepared for those systems and components requiring special inspection for seismic resistance as specified in Section 1707.1 by the registered design professional responsible for their design and shall be submitted for approval in accordance with Section 107.1, Chapter 1, Division II. Reference to seismic standards in lieu of detailed drawings is acceptable.

SECTION 1604
GENERAL DESIGN REQUIREMENTS

1604.1 General. Building, structures and parts thereof shall be designed and constructed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods, as permitted by the applicable material chapters.

1604.2 Strength. Buildings and other structures, and parts thereof, shall be designed and constructed to support safely the factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other structures, and parts thereof, shall be designed and constructed to support safely the nominal loads in load combinations defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.

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Loads and forces for occupancies or uses not covered in this chapter shall be subject to the approval of the building official.

1604.3 Serviceability. Structural systems and members thereof shall be designed to have adequate stiffness to limit deflections and lateral drift. See Section 12.12.1 of ASCE 7 for drift limits applicable to earthquake loading.

1604.3.1 Deflections. The deflections of structural members shall not exceed the more restrictive of the limitations of Sections 1604.3.2 through 1604.3.5 or that permitted by Table 1604.3.

TABLE 1604.3
DEFLECTION LIMITSa, b, c, h, i
CONSTRUCTION L S or Wf D+ Ld, g
For SI: 1 foot = 304.8 mm.
a. For structural roofing and siding made of formed metal sheets, the total load deflection shall not exceed l/60. For secondary roof structural members supporting formed metal roofing, the live load deflection shall not exceed l/150. For secondary wall members supporting formed metal siding, the design wind load deflection shall not exceed l/90. For roofs, this exception only applies when the metal sheets have no roof covering.
b. Interior partitions not exceeding 6 feet in height and flexible, folding and portable partitions are not governed by the provisions of this section. The deflection criterion for interior partitions is based on the horizontal load defined in Section 1607.13.
c. See Section 2403 for glass supports.
d. For wood structural members having a moisture content of less than 16 percent at time of installation and used under dry conditions, the deflection resulting from L + 0.5D is permitted to be substituted for the deflection resulting from L + D.
e. The above deflections do not ensure against ponding. Roofs that do not have sufficient slope or camber to assure adequate drainage shall be investigated for ponding. See Section 1611 for rain and ponding requirements and Section 1503.4 for roof drainage requirements.
f.The wind load is permitted to be taken as 0.7 times the “component and cladding” loads for the purpose of determining deflection limits herein.
g. For steel structural members, the dead load shall be taken as zero.
h. For aluminum structural members or aluminum panels used in skylights and sloped glazing framing, roofs or walls of sunroom additions or patio covers, not supporting edge of glass or aluminum sandwich panels, the total load deflection shall not exceed l/60. For continuous aluminum structural members supporting edge of glass, the total load deflection shall not exceed l/175 for each glass lite or l/60 for the entire length of the member, whichever is more stringent. For aluminum sandwich panels used in roofs or walls of sunroom additions or patio covers, the total load deflection shall not exceed l/120.
i. For cantilever members, l shall be taken as twice the length of the cantilever.
Roof members:e      
Supporting plaster ceiling l/360 l/360 l/240
Supporting nonplaster ceiling l/240 l/240 l/180
Not supporting ceiling l/180 l/180 l/120
Floor members l/360 — l/240
Exterior walls and interior partitions:      
With brittle finishes — l/240 —
With flexible finishes — l/120 —
Farm buildings — — l/180
Greenhouses — — l/120

1604.3.2 Reinforced concrete. The deflection of reinforced concrete structural members shall not exceed that permitted by ACI 318.

1604.3.3 Steel. The deflection of steel structural members shall not exceed that permitted by AISC 360, AISI S 100, ASCE 3, ASCE 8, SJI CJ-1.0, SJI JG-1.1, SJI K-1.1 or SJI LH/DLH-1.1, as applicable.

1604.3.4 Masonry. The deflection of masonry structural members shall not exceed that permitted by TMS 402/ACI 530/ASCE 5.

1604.3.5 Aluminum. The deflection of aluminum structural members shall not exceed that permitted by AA ADMI.

1604.3.6 Limits. Deflection of structural members over span, l, shall not exceed that permitted by Table 1604.3.

1604.4 Analysis. Load effects on structural members and their connections shall be determined by methods of structural analysis that take into account equilibrium, general stability, geometric compatibility and both short- and long-term material properties.

Members that tend to accumulate residual deformations under repeated service loads shall have included in their analysis the added eccentricities expected to occur during their service life.

Any system or method of construction to be used shall be based on a rational analysis in accordance with well-established principles of mechanics. Such analysis shall result in a system that provides a complete load path capable of transferring loads from their point of origin to the load-resisting elements.

The total lateral force shall be distributed to the various vertical elements of the lateral-force-resisting system in proportion to their rigidities, considering the rigidity of the horizontal bracing system or diaphragm. Rigid elements assumed not to be a part of the lateral-force-resisting system are permitted to be incorporated into buildings provided their effect on the action of the system is considered and provided for in the design. Except where diaphragms are flexible, or are permitted to be analyzed as flexible, provisions shall be made for the increased forces induced on resisting elements of the structural system resulting from torsion due to eccentricity between the center of application of the lateral forces and the center of rigidity of the lateral-force-resisting system.

Every structure shall be designed to resist the overturning effects caused by the lateral forces specified in this chapter. See Section 1609 for wind loads, Section 1610 for lateral soil loads and Section 1613 for earthquake loads.

1604.5 Occupancy category. Each building and structure shall be assigned an occupancy category in accordance with Table 1604.5.

1604.5.1 Multiple occupancies. Where a building or structure is occupied by two or more occupancies not included in the same occupancy category, it shall be assigned the classification of the highest occupancy category corresponding to the various occupancies. Where buildings or structures have two or more portions that are structurally separated, each portion shall be separately classified. Where a separated portion of a building or structure provides required access to, required egress from or shares life safety components with another portion having a higher occupancy category, both portions shall be assigned to the higher occupancy category.

1604.6 In-situ load tests. The building official is authorized to require an engineering analysis or a load test, or both, of any construction whenever there is reason to question the safety of

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the construction for the intended occupancy. Engineering analysis and load tests shall be conducted in accordance with Section 1714.

1604.7 Preconstruction load tests. Materials and methods of construction that are not capable of being designed by approved engineering analysis or that do not comply with the applicable material design standards listed in Chapter 35, or alternative test procedures in accordance with Section 1712, shall be load tested in accordance with Section 1715.

1604.8 Anchorage.

1604.8.1 General. Anchorage of the roof to walls and columns, and of walls and columns to foundations, shall be provided to resist the uplift and sliding forces that result from the application of the prescribed loads.

1604.8.2 Walls. Walls shall be anchored to floors, roofs and other structural elements that provide lateral support for the wall. Such anchorage shall provide a positive direct connection capable of resisting the horizontal forces specified in this chapter but not less than the minimum strength design horizontal force specified in Section 11.7.3 of ASCE 7, substituted for “E” in the load combinations of Section 1605.2 or 1605.3. Concrete and masonry walls shall be designed to resist bending between anchors where the anchor spacing exceeds 4 feet (1219 mm). Required anchors in masonry walls of hollow units or cavity walls shall be embedded in a reinforced grouted structural element of the wall. See Sections 1609 for wind design requirements and 1613 for earthquake design requirements.

1604.8.3 Decks. Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where

TABLE 1604.5
OCCUPANCY CATEGORY OF BUILDINGS AND OTHER STRUCTURES
OCCUPANCY CATEGORY NATURE OF OCCUPANCY
a. For purposes of occupant load calculation, occupancies required by Table 1004.1.1 to use gross floor area calculations shall be permitted to use net floor areas to determine the total occupant load.
I Buildings and other structures that represent a low hazard to human life in the event of failure, including but not limited to:
  • Agricultural facilities.
  • Certain temporary facilities.
  • Minor storage facilities.
II Buildings and other structures except those listed in Occupancy Categories I, III and IV
III Buildings and other structures that represent a substantial hazard to human life in the event of failure, including but not limited to:
  • Buildings and other structures whose primary occupancy is public assembly with an occupant load greater than 300.
  • Buildings and other structures containing elementary school, secondary school or day care facilities with an occupant load greater than 250.
  • Buildings and other structures containing adult education facilities, such as colleges and universities, with an occupant load greater than 500.
  • Group I-2 occupancies with an occupant load of 50 or more resident patients but not having surgery or emergency treatment facilities.
  • Group I-3 occupancies.
  • Any other occupancy with an occupant load greater than 5,000a.
  • Power-generating stations, water treatment facilities for potable water, waste water treatment facilities and other public utility facilities not included in Occupancy Category IV.
  • Buildings and other structures not included in Occupancy Category IV containing sufficient quantities of toxic or explosive substances to be dangerous to the public if released.
IV Buildings and other structures designated as essential facilities, including but not limited to:
  • Group I-2 occupancies having surgery or emergency treatment facilities. [OSHPD 3] For OSHPD 3 facilities, see Section 308.3.2.
  • Fire, rescue, ambulance and police stations and emergency vehicle garages.
  • Designated earthquake, hurricane or other emergency shelters.
  • Designated emergency preparedness, communications and operations centers and other facilities required for emergency response.
  • Power-generating stations and other public utility facilities required as emergency backup facilities for Occupancy Category IV structures.
  • Structures containing highly toxic materials as defined by Section 307 where the quantity of the material exceeds the maximum allowable quantities of Table 307.1(2).
  • Aviation control towers, air traffic control centers and emergency aircraft hangars.
  • Buildings and other structures having critical national defense functions.
  • Water storage facilities and pump structures required to maintain water pressure for fire suppression.
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positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting. Connections of decks with cantilevered framing members to exterior walls or other framing members shall be designed for both of the following:

  1. The reactions resulting from the dead load and live load specified in Table 1607.1, or the snow load specified in Section 1608, in accordance with Section 1605, acting on all portions of the deck.
  2. The reactions resulting from the dead load and live load specified in Table 1607.1, or the snow load specified in Section 1608, in accordance with Section 1605, acting on the cantilevered portion of the deck, and no live load or snow load on the remaining portion of the deck.

1604.9 Counteracting structural actions. Structural members, systems, components and cladding shall be designed to resist forces due to earthquake and wind, with consideration of overturning, sliding and uplift. Continuous load paths shall be provided for transmitting these forces to the foundation. Where sliding is used to isolate the elements, the effects of friction between sliding elements shall be included as a force.

1604.10 Wind and seismic detailing. Lateral-force-resisting systems shall meet seismic detailing requirements and limitations prescribed in this code and ASCE 7, excluding Chapter 14 and Appendix 11A, even when wind load effects are greater than seismic load effects.

SECTION 1605
LOAD COMBINATIONS

1605.1 General. Buildings and other structures and portions thereof shall be designed to resist:

  1. The load combinations specified in Section 1605.2, 1605.3.1 or 1605.3.2,
  2. The load combinations specified in Chapters 18 through 23, and
  3. The load combinations with overstrength factor specified in Section 12.4.3.2 of ASCE 7 where required by Section 12.2.5.2, 12.3.3.3 or 12.10.2.1 of ASCE 7. With the simplified procedure of ASCE 7 Section 12.14, the load combinations with overstrength factor of Section 12.14.3.2 of ASCE 7 shall be used.

Applicable loads shall be considered, including both earthquake and wind, in accordance with the specified load combinations. Each load combination shall also be investigated with one or more of the variable loads set to zero.

Where the load combinations with overstrength factor in Section 12.4.3.2 of ASCE 7 apply, they shall be used as follows:

  1. The basic combinations for strength design with overstrength factor in lieu of Equations 16-5 and 16-7 in Section 1605.2.1.
  2. The basic combinations for allowable stress design with overstrength factor in lieu of Equations 16-12, 16-13 and 16-15 in Section 1605.3.1.
  3. The basic combinations for allowable stress design with overstrength factor in lieu of Equations 16-20 and 16-21 in Section 1605.3.2.

1605.1.1 Stability. Regardless of which load combinations are used to design for strength, where overall structure stability (such as stability against overturning, sliding, or buoyancy) is being verified, use of the load combinations specified in Section 1605.2 or 1605.3 shall be permitted. Where the load combinations specified in Section 1605.2 are used, strength reduction factors applicable to soil resistance shall be provided by a registered design professional. The stability of retaining walls shall be verified in accordance with Section 1807.2.3.

1605.2 Load combinations using strength design or load and resistance factor design.

1605.2.1 Basic load combinations. Where strength design or load and resistance factor design is used, structures and portions thereof shall resist the most critical effects from the following combinations of factored loads:

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where:

f1 = 1 for floors in places of public assembly, for live loads in excess of 100 pounds per square foot (4.79 kN/m2), and for parking garage live load, and

= 0.5 for other live loads.

f2 = 0.7 for roof configurations (such as saw tooth) that do not shed snow off the structure, and

= 0.2 for other roof configurations.

Exception: Where other factored load combinations are specifically required by the provisions of this code, such combinations shall take precedence.

1605.2.2 Flood loads. Where flood loads, Fa, are to be considered in the design, the load combinations of Section 2.3.3 of ASCE 7 shall be used.

1605.3 Load combinations using allowable stress design.

1605.3.1 Basic load combinations. Where allowable stress design (working stress design), as permitted by this code, is used, structures and portions thereof shall resist the most critical effects resulting from the following combinations of loads:

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Exceptions:

  1. Crane book loads need not be combined with roof live load or with more than three-fourths of the snow load or one-half of the wind load.
  2. Flat roof snow loads of 30 psf (1.44 kN/m2) or less and roof live loads of 30 psf or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.

1605.3.1.1 Stress increases. Increases in allowable stresses specified in the appropriate material chapter or the referenced standards shall not be used with the load combinations of Section 1605.3.1, except that increases shall be permitted in accordance with Chapter 23.

1605.3.1.2 Flood loads. Where flood loads, Fa, are to be considered in design, the load combinations of Section 2.4.2 of ASCE 7 shall be used.

1605.3.2 Alternative basic load combinations. In lieu of the basic load combinations specified in Section 1605.3.1, structures and portions thereof shall be permitted to be designed for the most critical effects resulting from the following combinations. When using these alternative basic load combinations that include wind or seismic loads, allowable stresses are permitted to be increased or load combinations reduced where permitted by the material chapter of this code or the referenced standards. For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely to be in place during a design wind event shall be used. Where wind loads are calculated in accordance with Chapter 6 of ASCE 7, the coefficient ω in the following equations shall be taken as 1.3. For other wind loads, ω shall be taken as 1. When using these alternative load combinations to evaluate sliding, overturning and soil bearing at the soil-structure interface, the reduction of foundation overturning from Section 12.13.4 in ASCE 7 shall not be used. When using these alternative basic load combinations for proportioning foundations for loadings, which include seismic loads, the vertical seismic load effect, Ev, in Equation 12.4-4 of ASCE 7 is permitted to be taken equal to zero.

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Exception:

  1. Crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind load.
  2. Flat roof snow loads of 30 psf (1.44 kN/m2) or less and roof live loads of 30 psf or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.

1605.3.2.1 Other loads. Where F, H or T are to be considered in the design, each applicable load shall be added to the combinations specified in Section 1605.3.2

1605.4 Heliports and helistops. Heliport and helistop landing areas shall be designed for the following loads, combined in accordance with Section 1605:

  1. Dead load, D, plus the gross weight of the helicopter,Dh, plus snow load, S.
  2. Dead load, D, plus two single concentrated impact loads, L, approximately 8 feet (2438 mm) apart applied any where on the touchdown pad (representing each of the helicopter' s two main landing gear, whether skid type or wheeled type), having a magnitude of 0.75 times the gross weight of the helicopter. Both loads acting together total 1.5 times the gross weight of the helicopter.
  3. Dead load, D, plus a uniform live load,L, of 100 psf (4.79 kN/m2).

Exception: Landing areas designed for helicopters with gross weights not exceeding 3,000 pounds (13.34 kN) in accordance with Items 1 and 2 shall be permitted to be designed using a 40 psf (1.92 kN/m2) uniform live load in Item 3, provided the landing area is identified with a 3,000 pound (13.34 kN) weight limitation. This 40 psf (1.92 kN/m2) uniform live load shall not be reduced. The landing area weight limitation shall be indicated by the numeral “3” (kips) located in the bottom right corner of the landing area as viewed from the primary approach path. The indication for the landing area weight limitation shall be a minimum 5 feet (1524 mm) in height.

SECTION 1606
DEAD LOADS

1606.1 General. Dead loads are those loads defined in Section 1602.1. Dead loads shall be considered permanent loads.

1606.2 Design dead load. For purposes of design, the actual weights of materials of construction and fixed service equipment shall be used. In the absence of definite information, values used shall be subject to the approval of the building official.

SECTION 1607
LIVE LOADS

1607.1 General. Live loads are those loads defined in Section 1602.1.

TABLE 1607.1
MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS, Lo, AND
MINIMUM CONCENTRATED LIVE LOADSg
OCCUPANCY OR USE UNIFORM (psf) CONCENTRATED (lbs.)
1. Apartments (see residential) — —
2. Access floor systems    
Office use 50 2,000
Computer use 100 2,000
3. Armories and drill rooms 150 —
4. Assembly areas and theaters    
Fixed seats (fastened to floor) 60  
Follow spot, projections and control rooms 50  
Lobbies 100 —
Movable seats 100  
Stages and platforms 125  
Other assembly areas 100  
5. Balconies (exterior) and decksh Same as occupancy served —
6. Bowling alleys 75 —
7. Catwalks 40 300
8. Cornices 60 —
9. Corridors, except as otherwise indicated 100 —
10. Dance halls and ballrooms 100 —
11. Dining rooms and restaurants 100 —
12. Dwellings (see residential) — —
13. Elevator machine room grating (on area of 4 in2) — 300
14. Finish light floor plate construction (on area of 1 in2) — 200
15. Fire escapes 100 —
On single-family dwellings only 40
16. Garages (passenger vehicles only) 40 Note a
Trucks and buses See Section 1607.6
17. Grandstands
(see stadium and arena bleachers)		 —
18. Gymnasiums, main floors and balconies 100
19. Handrails, guards and grab bars See Section 1607.7
20. Hospitals  
Corridors above first floor 80
Operating rooms, laboratories 60
Patient rooms 40
21. Hotels (see residential) —
22. Libraries  
Corridors above first floor 80
Reading rooms 60
Stack rooms 150b
23. Manufacturing  
Heavy 250
Light 125
24. Marquees 75  
25. Office buildings    
Corridors above first floor 80 2,000
File and computer rooms shall be designed for heavier loads based on anticipated occupancy — —
Lobbies and first-floor corridors 100 2,000
Offices 50 2,000
26. Penal institutions    
Cell blocks 40 —
Corridors 100  
27. Residential    
One- and two-family dwellings  
Uninhabitable attics without storagei 10  
Uninhabitable attics with limited storagei, j, k 20  
Habitable attics and sleeping areas 30 —
All other areas 40  
Hotels and multifamily dwellings    
Private rooms and corridors serving them 40  
Public rooms and corridors serving them 100  
28. Reviewing stands, grandstands and bleachers Note c
29. Roofs  
All roof surfaces subject to maintenance workers  
Awnings and canopies  
Fabric construction supported by a lightweight rigid skeleton structure 5
nonreducible
All other construction 20
Ordinary flat, pitched, and curved roofs 20
Primary roof members, exposed to a work floor  
Single panel point of lower chord of roof trusses or any point along primary structural members supporting roofs:  
Over manufacturing, storage warehouses, and repair garages  
All other occupancies  
Roofs used for other special purposes Note 1
Roofs used for promenade purposes 60
Roofs used for roof gardens or assembley purposes 100
30. Schools  
Classrooms 40
Corridors above first floor 80
First-floor corridors 100
31. Scuttles, skylight ribs and accessible ceilings —
32. Sidewalks, vehicular driveways and yards, subject to trucking 250d
33. Skating rinks 100
34. Stadiums and arenas  
Bleachers 100c
Fixed seats (fastened to floor) 60c 12
35. Stairs and exits    
One-and two-family dwellings 40 Note f
All other 100  
36. Storage warehouses (shall be designed for heavier loads if required for anticipated storage)    
Heavy 250  
Light 125  
37. Stores    
Retail    
First floor 100 1,000
Upper floors 75 1,000
Wholesale, all floors 125 1,000
38. Vehicle barrier systems See Section 1607.7.3
39. Walkways and elevated platforms(other than exitways) 60 —
40. Yards and terraces, pedestrians 100 —
41. [OSHPD 2] Storage racks and wall-hung cabinets Total loadsm —
For SI: 1 inch= 25.4 mm, 1 square inch=645.16 mm2,
1 square foot= 0.0929 m2,
1 pound per square foot = 0.0479 kN/m2,1 pound= 0.004448 kN,
1 pound per cubic foot= 16 kg/m3
a. Floors in garages or portions of buildings used for the storage of motor vehicles shall be designed for the uniformly distributed live loads of Table 1607.1 or the following concentrated loads: (1) for garages restricted to passenger vehicles accommodating not more than nine passengers, 3,000 pounds acting on an area of 4.5 inches by 4.5 inches;(2) for mechanical parking structures without slab or deck which are used for storing passenger vehicles only, 2,250 pounds per wheel.
b. The loading applies to stack room floors that support nonmobile, double-faced library bookstacks, subject to the following limitations:
1. The nominal bookstack unit height shall not exceed 90 inches;
2. The nominal shelf depth shall not exceed 12 inches for each face; and
3. Parallel rows of double-faced bookstacks shall be separated by aisles not less than 36 inches wide.
c. Design in accordance with ICC 300.
d. Other uniform loads in accordance with an approved method which contains provisions for truck loadings shall also be considered where appropriate.
e. The concentrated wheel load shall be applied on an area of 4.5 inches by 4.5 inches.
f. Minimum concentrated load on stair treads (on area of 4 square inches) is 300 pounds.
g. Where snow loads occur that are in excess of the design conditions, the structure shall be designed to support the loads due to the increased loads caused by drift buildup or a greater snow design determined by the building official (see Section 1608). For special-purpose roofs, see Section 1607.11.2.2.
h. See Section 1604.8.3 for decks attached to exterior walls.
i. Attics without storage are those where the maximum clear height between the joist and rafter is less than 42 inches, or where there are not two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide, or greater, located within the plane of the truss. For attics without storage, this live load need not be assumed to act concurrently with any other live load requirements.
j. For attics with limited storage and constructed with trusses, this live load need only be applied to those portions of the bottom chord where there are two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide or greater, located within the plane of the truss. The rectangle shall fit between the top of the bottom chord and the bottom of any other truss member, provided that each of the following criteria is met:
i. The attic area is accessible by a pull-down stairway or framed opening in accordance with Section 1209.2, and
ii. The truss shall have a bottom chord pitch less than 2:12.
iii. Bottom chords of trusses shall be designed for the greater of actual imposed dead load or 10 psf, uniformly distributed over the entire span.
k. Attic spaces served by a fixed stair shall be designed to support the minimum live load specified for habitable attics and sleeping rooms.
l. Roofs used for other special purposes shall be designed for appropriate loads as approved by the building official.
m. [OSHPD 2] The minimum vertical design live load shall be as follows:
Paper media:
12-inch-deep (305 mm) shelf 33 pounds per lineal foot (482 N/m)
15-inch-deep (381 mm) shelf 41 pounds per lineal foot (598 N/m), or
33 pounds per cubic foot (5183 N/m3) per total volume of the rack or cabinet, whichever is less.
Film media:
18-inch-deep (457 mm) shelf 100 pounds per lineal foot (1459 N/m), or 50 pounds per cubic foot (7853 N/m3) per total volume of the rack or cabinet, whichever is less.
Other media:
20 pounds per cubic foot (311 N/m3) or 20 pounds per square foot (958 Pa), whichever is less, but not less than actual loads.

1607.2 Loads not specified. For occupancies or uses not designated in Table 1607.1, the live load shall be determined in accordance with a method approved by the building official.

1607.3 Uniform live loads. The live loads used in the design of buildings and other structures shall be the maximum loads expected by the intended use or occupancy but shall in no case be less than the minimum uniformly distributed unit loads required by Table 1607.1.

1607.4 Concentrated loads. Floors and other similar surfaces shall be designed to support the uniformly distributed live loads prescribed in Section 1607.3 or the concentrated load, in pounds (kilonewtons), given in Table 1607.1, whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall be assumed to be uniformly distributed over an area 2 ½ feet by 2½feet [6¼ square feet (0.58 m2)] and shall be located so as to produce the maximum load effects in the structural members.

1607.5 Partition loads. In office buildings and in other buildings where partition locations are subject to change, provisions for partition weight shall be made, whether or not partitions are shown on the construction documents, unless the specified live load exceeds 80 psf (3.83 kN/m2), The partition load shall not be less than a uniformly distributed live load of 15 psf (0.75 kN/m2).

1607.6 Truck and bus garages. Minimum live loads for garages having trucks or buses shall be as specified in Table 1607.6, but shall not be less than 50 psf (2.40 kN/m2), unless other loads are specifically justified and approved by the building official. Actual loads shall be used where they are greater than the loads specified in the table.

1607.6.1 Truck and bus garage live load application. The concentrated load and uniform load shall be uniformly distributed over a 10-foot (3048 mm) width on a line normal to the centerline of the lane placed within a 12-foot-wide (3658 mm) lane. The loads shall be placed within their individual lanes so as to produce the maximum stress in each structural member. Single spans shall be designed for the uniform load in Table 1607.6 and one simultaneous concentrated load positioned to produce the maximum effect. Multiple spans shall be designed for the uniform load in Table 1607.6 on the spans and two simultaneous concentrated loads in two spans positioned to produce the maximum negative moment effect. Multiple span design loads, for other effects, shall be the same as for single spans.

13
TABLE 1607.6
UNIFORM AND CONCENTRATED LOADS
LOADING CLASSa UNIFORM LOAD (pounds/linear foot of lane) CONCENTRATED LOAD(pounds)b
For moment design For shear design
For SI: 1 pound per linear foot = 0.01459 kN/m, 1 pound=0.004448kN, 1 ton = 8.90 kN.
a. An H loading class designates a two-axle truck with a semitrailer. An HS loading class designates a tractor truck with a semitrailer. The numbers following the letter classification indicate the gross weight in tons of the standard truck and the year the loadings were instituted.
b. See Section 1607.6.1 for the loading of multiple spans.
H20-44 and HS20-44 640 18,000 26,000
H15-44 and HS15-44 480 13,500 19,500

1607.7 Loads on handrails, guards, grab bars, shower seats,dressing room bench seats and vehicle barrier systems. Handrails,s, grab bars, accessible seats, accessible benches and vehicle barrier systems shall be designed and constructed to the structural loading conditions set forth in this section.

1607.7.1 Handrails and guards. Handrails and guards shall be designed to resist a load of 50 pounds per linear foot (plf)(0.73 kN/m) applied in any direction at the top and to transfer this load through the supports to the structure. Glass handrail assemblies and guards shall also comply with Section 2407.

Exceptions:

  1. For one- and two-family dwellings, only the single concentrated load required by Section 1607.7.1.1 shall be applied.
  2. In Group I-3, F, H and S occupancies, for areas that are not accessible to the general public and that have an occupant load less than 50, the minimum load shall be 20 pounds per foot (0.29 kN/m).

1607.7.1.1 Concentrated load. Handrails and guards shall be able to resist a single concentrated load of 200 pounds (0.89 kN), applied in any direction at any point along the top, and to transfer this load through the supports to the structure. This load need not be assumed to act concurrently with the loads specified in Section 1607.7.1.

1607.7.1.2 Components. Intermediate rails (all those except the handrail), balusters and panel fillers shall be designed to withstand a horizontally applied normal load of 50 pounds (0.22 kN) on an area equal to 1 square foot (0.093m2), including openings and space between rails. Reactions due to this loading are not required to be superimposed with those of Section 1607.7.1 or 1607.7.1.1.

1607.7.2 Grab bars, shower seats and dressing room bench seats. Grab bars, shower seats and dressing room bench seat systems shall be designed to resist a single concentrated load of 250 pounds (1.11 kN) applied in any direction at any point.[DSA-AC & HCD 1-AC] See Chapter 11A, Section 1127A. 4, and Chapter 11 B, Sections 115B.7.2 and 1117B.8, for grab bars, shower seats and dressing room bench seats, as applicable.

1607.7.3 Vehicle barrier systems. Vehicle barrier systems for passenger vehicles shall be designed to resist a single load of 6,000 pounds (26.70 kN) applied horizontally in any direction to the barrier system and shall have anchorage or attachment capable of transmitting this load to the structure. For design of the system, two loading conditions shall be analyzed. The first condition shall apply the load at a height of 1 foot, 6 inches (457 mm) above the floor or ramp surface. The second loading condition shall apply the load at 2 feet, 3 inches (686 mm) above the floor or ramp surface. The more severe load condition shall govern the design of the barrier restraint system. The load shall be assumed to act on an area not to exceed 1 square foot (0.0929 m2), and is not required to be assumed to act concurrently with any handrail or guard loadings specified in Section 1607.7.1. Garages accommodating trucks and buses shall be designed in accordance with an approved method that contains provisions for traffic railings.

1607.8 Impact loads. The live loads specified in Section 1607.3 include allowance for impact conditions. Provisions shall be made in the structural design for uses and loads that involve unusual vibration and impact forces.

1607.8.1 Elevators. Elevator loads shall be increased by 100 percent for impact and the structural supports shall be designed within the limits of deflection prescribed by ASME A17.1.

1607.8.2 Machinery. For the purpose of design, the weight of machinery and moving loads shall be increased as follows to allow for impact: (1)elevator machinery, 100 percent; (2) light machinery, shaft- or motor-driven, 20 percent; (3) reciprocating machinery or power-driven units, 50 percent; (4) hangers for floors or balconies, 33 percent. Percentages shall be increased where specified by the manufacturer.

1607.9 Reduction in live loads. Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607.1 are permitted to be reduced in accordance with Section 1607.9.1 or 1607.9.2. Roof uniform live loads, other than special purpose roofs of Section 1607.11.2.2, are permitted to be reduced in accordance with Section 1607.11.2. Roof uniform live loads of special purpose roofs are permitted to be reduced in accordance with Section 1607.9.1 or 1607.9.2.

1607.9.1 General. Subject to the limitations of Sections 1607.9.1.1 through 1607.9.1.4, members for which a value of KLLAT is 400 square feet (37.16 m2) or more are permitted to be designed for a reduced live load in accordance with the following equation:

Image

where:

L = Reduced design live load per square foot (meter) of area supported by the member.

14

Lo = Unreduced design live load per square foot (meter) of area supported by the member (see Table 1607.1).

KLL = Live load element factor (see Table 1607.9.1).

AT = Tributary area, in square feet (square meters).

L shall not be less than 0.50 Lo for members supporting one floor and L shall not be less than 0.40Lo for members supporting two or more floors.

TABLE 1607.9.1
LIVE LOAD ELEMENT FACTOR, KLL
ELEMENT KLL
Interior columns 4
Exterior columns without cantilever slabs 4
Edge columns with cantilever slabs 3
Corner columns with cantilever slabs 2
Edge beams without cantilever slabs 2
Interior beams 2
All other members not identified above including:  
Edge beams with cantilever slabs  
Cantilever beams  
One-way slabs 1
Two-way slabs  
Members without provisions for continuous shear transfer normal to their span  

1607.9.1.1 One-way slabs. The tributary area, AT, for use in Equation 16-22 for one-way slabs shall not exceed an area defined by the slab span times a width normal to the span of 1.5 times the slab span.

1607.9.1.2 Heavy live loads. Live loads that exceed 100 psf (4.79 kN/m2) shall not be reduced.

Exceptions:

  1. The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607.9.1.
  2. For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.

1607.9.1.3 Passenger vehicle garages. The live loads shall not be reduced in passenger vehicle garages.

Exception: The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607.9.1.

1607.9.1.4 Group A occupancies. Live loads of 100 psf (4.79 kN/m2) and at areas where fixed seats are located shall not be reduced in Group A occupancies.

1607.9.1.5 Roof members. Live loads of 100 psf (4.79 kN/m2) or less shall not be reduced for roof members except as specified in Section 1607.11.2.

1607.9.2 Alternate floor live load reduction. As an alternative to Section 1607.9.1 floor live loads are permitted to be reduced in accordance with the following provisions. Such reductions shall apply to slab systems, beams, girders, columns, piers, walls and foundations.

  1. A reduction shall not be permitter in Group A occupancies.
  2. A reduction shall not be permitted where the live load exceeds 100 psf (4.79kN/m2) except that the design live load for members supporting two or more floors is permitted to be reduced by 20 percent.

    Exception: For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.

  3. A reduction shall not be permitted in passenger vehicle parking garages except that the live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent.
  4. For live loads not exceeding 100 psf (4.79 kN/m2), the design live load for any structural member supporting 150 square feet (13.94 m2)or more is permitted to be reduced in accordance with Equation 16-23.
  5. For one-way slabs, the area, A, for use in Equation 16-23 shall not exceed the product of the slab span and a width normal to the span of 0.5 times the slab span.

Image

For SI: R = 0.861 (A - 13.94)

Such reduction shall not exceed the smallest of:

  1. 40 percent for horizontal members:
  2. 60 percent for vertical members; or
  3. R as determined by the following equation.

Image

where:

A = Area of floor supported by the member, square feet (m2).

D = Dead load per square foot (m2) of area supported.

Lo = Unreduced live load per square foot (m2) of areas supported.

R = Reduction in percent.

1607.10 Distribution of floor loads. Where uniform floor live loads are involved in the design of structural members arranged so as to create continuity, the minimum applied loads shall be the full dead loads on all spans in combination with the floor live loads on spans selected to produce the greatest effect at each location under consideration. It shall be permitted to reduce floor live loads in accordance with Section 1607.9.

15

1607.11 Roof loads. The structural supports of roofs and marquees shall be designed to resist wind and, where applicable, snow and earthquake loads, in addition to the dead load of construction and the appropriate live loads as prescribed in this section, or as set forth in Table 1607.1. The live loads acting on a sloping surface shall be assumed to act vertically on the horizontal projection of that surface.

1607.11.1 Distribution of roof loads. Where uniform roof live loads are reduced to less than 20 psf (0.96 kN/m2) in accordance with Section 1607.11.2.1 and are applied to the design of structural members arranged so as to create continuity, the reduced roof live load shall be applied to adjacent spans or to alternate spans, whichever produces the most unfavorable load effect. See Section 1607.11.2 for reductions in minimum roof live loads and Section 7.5 of ASCE 7 for partial snow loading.

1607.11.2 Reduction in roof live loads. The minimum uniformly distributed live loads of roofs and marquees, Lo, in Table 1607.1 are permitted to be reduced in accordance with Section 1607.11.2.1 or 1607.11.2.2.

1607.11.2.1 Flat, pitched and curved roofs. Ordinary flat, pitched and curved roofs, and awnings and canopies other than of fabric construction supported by light-weight rigid skeleton structures, are permitted to be designed for a reduced roof live load as specified in the following equations or other controlling combinations of loads in Section 1605, whichever produces the greater load. In structures such as greenhouses, where special scaffolding is used as a work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equations shall not be used unless approved by the building official. Such structures shall be designed for a minimum roof live load of 12 psf (0.58 kN/m2).

Image

where: 12 ≤ Lr ≤ 20

For SI: Lr = LoR1R2

where: 0.58 ≤ Lr ≤ 0.96

Lr = Reduced live load per square foot (m2) of horizontal projection in pounds per square foot (kN/m2)

The reduction factors R1 and R2 shall be determined as follows:

Image

For SI: 1.2 – 0.001At for 18.58 square meters <At <55.74 square meters

Image

where:

At = Tributary area (span length multiplied by effective width) in square feet (m2 supported by any structural member, and

Image

where:

F = For a sloped roof, the number of inches of rise per foot (for SI: F = 0.12 × slope, with slope expressed as a percentage), or for an arch or dome, the rise-to-span ratio multiplied by 32.

1607.11.2.2 Special-purpose roofs. Roofs used for promenade purposes, roof gardens, assembly purposes or other special purposes, and marquees, shall be designed for a minimum live load, Lo, as specified in Table 1607.1. Such live loads are permitted to be reduced in accordance with Section 1607.9. Live loads of 100 psf (4.79 kN/m2) or more at areas of roofs classified as Group A occupancies shall not be reduced.

1607.11.3 Landscaped roofs. Where roofs are to be landscaped, the uniform design live load in the landscaped area shall be 20 psf (0.958 kN/m2). The weight of the landscaping materials shall be considered as dead load and shall be computed on the basis of saturation of the soil.

1607.11.4 Awnings and canopies. Awnings and canopies shall be designed for uniform live loads as required in Table 1607.1 as well as for snow loads and wind loads as specified in Sections 1608 and 1609.

1607.12 Crane loads. The crane live load shall be the rated capacity of the crane. Design loads for the runway beams, including connections and support brackets, of moving bridge cranes and monorail cranes shall include the maximum wheel loads of the crane and the vertical impact, lateral and longitudinal forces induced by the moving crane.

1607.12.1 Maximum wheel load. The maximum wheel loads shall be the wheel loads produced by the weight of the bridge, as applicable, plus the sum of the rated capacity and the weight of the trolley with the trolley positioned on its runway at the location where the resulting load effect is maximum.

1607.12.2 Vertical impact force. The maximum wheel loads of the crane shall be increased by the percentages shown below to determine the induced vertical impact or vibration force:

Monorail cranes (powered) 25 percent

Cab-operated or remotely operated bridge cranes (powered) 25 percent

Pendant-operated bridge cranes (powered) 10 percent

Bridge cranes or monorail cranes with hand-geared bridge, trolley and hoist 0 percent

1607.12.3 Lateral force. The lateral force on crane runway beams with electrically powered trolleys shall be calculated

16

as 20 percent of the sum of the rated capacity of the crane and the weight of the hoist and trolley. The lateral force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction perpendicular to the beam; and shall be distributed according to the lateral stiffness of the runway beam and supporting structure.

1607.12.4 Longitudinal force. The longitudinal force on crane runway beams, except for bridge cranes with hand-geared bridges, shall be calculated as 10 percent of the maximum wheel loads of the crane. The longitudinal force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction parallel to the beam.

1607.13 Interior walls and partitions. Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2).

Exception: Fabric partitions complying with Section 1607.13.1 shall not be required to resist the minimum horizontal load of 5 psf (0.24 kN/m2).

1607.13.1 Fabric partitions. Fabric partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the following load conditions:

  1. A horizontal distributed load of 5 psf (0.24 kN/m2) applied to the partition framing. The total area used to determine the distributed load shall be the area of the fabric face between the framing members to which the fabric is attached. The total distributed load shall be uniformly applied to such framing members in proportion to the length of each member.
  2. A concentrated load of 40 pounds (0.176 kN) applied to an 8-inch diameter (203 mm) area [50.3 square inches (32 452 mm2)] of the fabric face at a height of 54 inches (1372 mm) above the floor.

SECTION 1608
SNOW LOADS

1608.1 General. Design snow loads shall be determined in accordance with Chapter 7 of ASCE 7, but the design roof load shall not be less than that determined by Section 1607.

1608.2 Ground snow loads. The ground snow loads to be used in determining the design snow loads for roofs shall be determined in accordance with ASCE 7 or Figure 1608.2 for the contiguous United States and Table 1608.2 for Alaska. Site-specific case studies shall be made in areas designated “CS” in Figure 1608.2. Ground snow loads for sites at elevations above the limits indicated in Figure 1608.2 and for all sites within the CS areas shall be approved. Ground snow load determination for such sites shall be based on an extreme value statistical analysis of data available in the vicinity of the site using a value with a 2-percent annual probability of being exceeded (50-year mean recurrence interval). Snow loads are zero for Hawaii, except in mountainous regions as approved by the building official.

TABLE 1608.2
GROUND SNOW LOADS, pg, FOR ALASKAN LOCATIONS
LOCATIONPOUNDS PER SQUARE FOOTLOCATIONPOUNDS PER SQUARE FOOTLOCATIONPOUNDS PER SQUARE FOOT
For SI: 1 pound per square foot = 0.0479kN/m2.
Adak30Galena60Petersburg150
Anchorage50Gulkana70St. Paul Islands40
Angoon70Homer40Seward50
Barrow25Juneau60Shemya25
Barter Island35Kenai70Sitka50
Bethel40Kodiak30Talkeetna120
Big Delta50Kotzebue60Unalakleet50
Cold Bay25McGrath70Valdez160
Cordova100Nenana80Whittier300
Fairbanks60Nome70Wrangell60
Fort Yukon60Palmer50Yakutat150
17

FIGURE 1608.2 GROUND SNOW LOADS, pg FOR THE UNITED STATES (psf)

FIGURE 1608.2
GROUND SNOW LOADS, pg FOR THE UNITED STATES (psf)

18

FIGURE 1608.2-continued GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)

FIGURE 1608.2–continued
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)

19

SECTION 1609
WIND LOADS

1609.1 Applications. Buildings, structures and parts thereof shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for the effect of shielding by other structures.

1609.1.1 Determination of wind loads. Wind loads on every building or structure shall be determined in accordance with Chapter 6 of ASCE 7 or provisions of the alternate all-heights method in Section 1609.6. The type of opening protection required, the basic wind speed and the exposure category for a site is permitted to be determined in accordance with Section 1609 or ASCE 7. Wind shall be assumed to come from any horizontal direction and wind pressures shall be assumed to act normal to the surface considered.

Exceptions:

  1. Subject to the limitations of Section 1609.1.1.1, the provisions of ICC 600 shall be permitted for applicable Group R-2 and R-3 buildings.
  2. Subject to the limitations of Section 1609.1.1.1, residential structures using the provisions of the AF&PA WFCM.
  3. Subject to the limitations of Section 1609.1.1.1, residential structures using the provisions of AISI S230.
  4. Designs using NAAMM FP 1001.
  5. Designs using TIA-222 for antenna-supporting structures and antennas.

  6. Wind tunnel tests in accordance with Section 6.6 of ASCE 7, subject to the limitations in Section 1609.1.1.2.

1609.1.1.1 Applicability. The provisions of ICC 600 are applicable only to buildings located within Exposure B or C as defined in Section 1609.4. The provisions of ICC 600, AF&PA WFCM and AISI S230 shall not apply to buildings sited on the upper half of an isolated hill, ridge or escarpment meeting the following conditions:

  1. The hill, ridge or escarpment is 60 feet (18 288 mm) or higher if located in Exposure B or 30 feet (9144 mm) or higher if located in Exposure C;
  2. The maximum average slope of the hill exceeds 10 percent; and
  3. The hill, ridge or escarpment is unobstructed upwind by other such topographic features for a distance from the high point of 50 times the height of the hill or 1 mile (1.61 km), whichever is greater.

1609.1.1.2 Wind tunnel test limitations. The lower limit on pressures for main wind-force-resisting systems and components and cladding shall be in accordance with Sections 1609.1.1.2.1 and 1609.1.1.2.2.

1609.1.1.2.1 Lower limits on main wind- force-resisting system. Base overturning moments determined from wind tunnel testing shall be limited to not less than 80 percent of the design base overturning moments determined in accordance with Section 6.5 of ASCE 7, unless specific testing is performed that demonstrates it is the aerodynamic coefficient of the building, rather than shielding from other structures, that is responsible for the lower values. The 80-percent limit shall be permitted to be adjusted by the ration of the frame load at critical wind directions as determined from wind tunnel testing without specific adjacent buildings, but including appropriate upwind roughness, to that determined in Section 6.5 of ASCE 7.

1609.1.1.2.2 Lower limits on components and cladding. The design pressures for components and cladding on walls or roofs shall be selected as the greater of the wind tunnel test results or 80 percent of the pressure obtained for Zone 4 for walls and Zone 1 for roofs as determined in Section 6.5 of ASCE 7, unless specific testing is performed that demonstrates it is the aerodynamic coefficient of the building, rather than shielding from nearby structures, that is responsible for the lower values. Alternatively, limited tests at a few wind directions without specific adjacent buildings, but in the presence of an appropriate upwind roughness, shall be permitted to be used to demonstrate that the lower pressures are due to the shape of the building and not to shielding.

1609.1.2 Protection of openings. In wind-borne debris regions, glazing in buildings shall be impact resistant or protected with an impact-resistant covering meeting the requirements of an approved impact-resistant standard or ASTM E 1996 and ASTM E 1886 referenced herein as follows:

  1. Glazed openings located within 30 feet (9144 mm) of grade shall meet the requirements of the large missile test of ASTM E 1996.
  2. Glazed openings located more than 30 feet (9144 mm) above grade shall meet the provisions of the small missile test of ASTM E 1996.

Exceptions:

  1. Wood structural panels with a minimum thickness of 7⁄16 inch (11.1 mm) and maximum panel span of 8 feet (2438 mm) shall be permitted for opening protection in one-and two-story buildings classified as Group R-3 or R-4 occupancy. Panels shall be precut so that they shall be attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be predrilled as required for the anchorage method and shall be secured with the attachment hardware provided. Attachments shall be designed to resist the components and cladding loads determined in accordance with the provisions of ASCE 7, with corrosion-resistant attachment hardware provided and anchors permanently installed on the building. Attachment in accordance with Table 1609.1.2 with corrosion-resistant attachment hardware provided and anchors permanently installed on the building is permitted for buildings with a mean roof height of 45 feet (13 716 mm) or less where wind speeds do not exceed 140 mph (63 m/s).20
  2. Glazing in Occupancy Category I buildings as defined in Section 1604.5, including greenhouses that are occupied for growing plants on a production or research basis, without public access shall be permitted to be unprotected.
  3. Glazing in Occupancy Category II, III or IV buildings located over 60 feet (18 288 mm) above the ground and over 30 feet (9144 mm) above aggregate surface roofs located within 1,500 feet (458 m) of the building shall be permitted to be unprotected.

1609.1.2.1 Louvers. Louvers protecting intake and exhaust ventilation ducts not assumed to be open that are located within 30 feet (9144 mm) of grade shall meet requirements of an approved impact-resisting standard or the large missile test of ASTM E 1996.

1609.1.2.2 Garage doors. Garage door glazed opening protection for wind-borne debris shall meet the requirements of an approved impact-resisting standard or ANSI⁄DASMA 115.

1609.2 Definitions. The following words and terms shall, for the purposes of Section 1609, have the meanings shown herein.

TABLE 1609.1.2
WIND-BORNE DEBRIS PROTECTION FASTENING SCHEDULE FOR WOOD STRUCTURAL PANELSa, b, c, d
FASTENER TYPE FASTENER SPACING (inches)
Panel
Span
≤ 4 feet		 4 feet <
Panel Span
≤ 6 feet		 6 feet <
Panel Span
≤ 8 feet
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N,
1 mile per hour = 0.447 m⁄s.
a. This table is based on 140 mph wind speeds and a 45-foot mean roof height.
b. Fasteners shall be installed at opposing ends of the wood structural panel. Fasteners shall be located a minimum of 1 inch from the edge of the panel.
c. Anchors shall penetrate through the exterior wall covering with an embedment length of 2 inches minimum into the building frame. Fasteners shall be located a minimum of 2½ inches from the edge of concrete block or concrete.
d. Where panels are attached to masonry or masonry⁄stucco, they shall be attached using vibration-resistant anchors having a minimum ultimate withdrawal capacity of 1,500 pounds.
No. 8 wood-screw-based anchor
with 2-inch embedment length		 16 10 8
No. 10 wood-screw-based
anchor with 2-inch embedment
length		 16 12 9
¼-inch diameter lag-screw-
based anchor with 2-inch
embedment length		 16 16 16

HURRICANE-PRONE REGIONS. Areas vulnerable to hurricanes defined as:

  1. The U. S. Atlantic Ocean and Gulf of Mexico coasts where the basic wind speed is greater than 90 mph (40 m⁄s) and
  2. Hawaii, Puerto Rico, Guam, Virgin Islands and American Samoa.

WIND-BORNE DEBRIS REGION. Portions of hurricane-prone regions that are within 1 mile (1.61 km) of the coastal mean high water line where the basic wind speed is 110 mph (48 m⁄s) or greater; or portions of hurricane-prone regions where the basic wind speed is 120 mph (53 m⁄s) or greater; or Hawaii.

1609.3 Basic wind speed. The basic wind speed, in mph, for the determination of the wind loads shall be determined by Figure 1609. Basic wind speed for the special wind regions indicated, near mountainous terrain and near gorges shall be in accordance with local jurisdiction requirements. Basic wind speeds determined by the local jurisdiction shall be in accordance with Section 6.5.4 of ASCE 7.

In nonhurricane-prone regions, when the basic wind speed is estimated from regional climatic data, the basic wind speed shall be not less than the wind speed associated with an annual probability of 0.02 (50-year mean recurrence interval), and the estimate shall be adjusted for equivalence to a 3-second gust wind speed at 33 feet (10 m) above ground in Exposure Category C. The data analysis shall be performed in accordance with Section 6.5.4.2 of ASCE 7.

1609.3.1 Wind speed conversion. When required, the 3-second gust basic wind speeds of Figure 1609 shall be converted to fastest-mile wind speeds, Vfm’ using Table 1609.3.1 or Equation 16–32.

Equation 16-32

where:

V3S = 3-second gust basic wind speed from Figure 1609.

1609.4 Exposure category. For each wind direction considered, an exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for the site at which the building or structure is to be constructed. Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well as from constructed features.

TABLE 1609.3.1
EQUIVALENT BASIC WIND SPEEDSa, b, c
For SI: 1 mile per hour = 0.44 m⁄s.
a. Linear interpolation is permitted.
b. V3S is the 3-second gust wind speed (mph).
c. Vfm is the fastest mile wind speed (mph).
V3S 85 90 100 105 110 120 125 130 140 145 150 160 170
Vfm 71 76 85 90 95 104 109 114 123 128 133 142 152
21

FIGURE 1609 BASIC WIND SPEED (3-SECOND GUST)

FIGURE 1609
BASIC WIND SPEED (3-SECOND GUST)

22

FIGURE 1609—continued BASIC WIND SPEED (3-SECOND GUST)

FIGURE 1609— continued
BASIC WIND SPEED (3 SECOND GUST)

23

FIGURE 1609— continued BASIC WIND SPEED (3-SECOND GUST) WESTERN GULF OF MEXICO HURRICANE COASTLINE

FIGURE 1609— continued
BASIC WIND SPEED (3-SECOND GUST) WESTERN GULF OF MEXICO HURRICANE COASTLINE"

24

FIGURE 1609 —continued BASIC WIND SPEED (3-SECOND GUST) EASTERN GULF OF MEXICO AND SOUTHEASTERN U.S. HURRICANE COASTLINE

FIGURE 1609 —continued
BASIC WIND SPEED (3-SECOND GUST) EASTERN GULF OF MEXICO AND SOUTHEASTERN U.S. HURRICANE COASTLINE

25

FIGURE 1609— continued BASIC WIND SPEED (3-SECOND GUST) MID AND NORTHERN ATLANTIC HURRICANE COASTLINE

FIGURE 1609— continued
BASIC WIND SPEED (3-SECOND GUST) MID AND NORTHERN ATLANTIC HURRICANE COASTLINE"

26

1609.4.1 Wind directions and sectors. For each selected wind direction at which the wind loads are to be evaluated, the exposure of the building or structure shall be determined for the two upwind sectors extending 45 degrees (0.79 rad) either side of the selected wind direction. The exposures in these two sectors shall be determined in accordance with Sections 1609.4.2 and 1609.4.3 and the exposure resulting in the highest wind loads shall be used to represent winds from that direction.

1609.4.2 Surface roughness categories. A ground surface roughness within each 45-degree (0.79 rad) sector shall be determined for a distance upwind of the site as defined in Section 1609.4.3 from the categories defined below, for the purpose of assigning an exposure category as defined in Section 1609.4.3.

Surface Roughness B. Urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.

Surface Roughness C. Open terrain with scattered obstructions having heights generally less than 30 feet (9144 mm). This category includes flat open country, grasslands, and all water surfaces in hurricane-prone regions.

Surface Roughness D. Flat, unobstructed areas and water surfaces outside hurricane-prone regions. This category includes smooth mud flats, salt flats and unbroken ice.

1609.4.3 Exposure categories. An exposure category shall be determined in accordance with the following:

Exposure B. Exposure B shall apply where the ground surface roughness condition, as defined by Surface Roughness B, prevails in the upwind direction for a distance of at least 2,600 feet (792 m) or 20 times the height of the building, whichever is greater.

Exception: For buildings whose mean roof height is less than or equal to 30 feet (9144 mm), the upwind distance is permitted to be reduced to 1,500 feet (457 mm).

Exposure C. Exposure C shall apply for all cases where Exposures B or D do not apply.

Exposure D. Exposure D shall apply where the ground surface roughness, as defined by Surface Roughness D, prevails in the upwind direction for a distance of at least 5,000 feet (1524 m) or 20 times the height of the building, whichever is greater. Exposure D shall extend inland from the shoreline for a distance of 600 feet (183 m) or 20 times the height of the building, whichever is greater.

1609.5 Roof systems.

1609.5.1 Roof deck. The roof deck shall be designed to withstand the wind pressures determined in accordance with ASCE 7.

1609.5.2 Roof coverings. Roof coverings shall comply with Section 1609.5.1.

Exception: Rigid tile roof coverings that are air permeable and installed over a roof deck complying with section 1609.5.1 are permitted to be designed in accordance with Section 1609.5.3.

Asphalt shingles installed over a roof deck complying with Section 1609.5.1 shall comply with the wind-resistance requirements of Section 1507.2.7.1.

1609.5.3 Rigid tile. Wind loads on rigid tile roof coverings shall be determined in accordance with the following equation:

Image

where:

b= Exposed width, feet (mm) of the roof tile.

CL = Lift coefficient. The lift coefficent for concrete and clay tile shall be 0.2 or shall be determined by test in accordance with Section 1716.2.

GCp = Roof pressure coefficient for each applicable roof zone determined from Chapter 6 of ASCE 7. Roof coefficients shall not be adjusted for internal pressure.

L = Length, feet (mm) of the roof tile.

La = Moment arm, feet (mm) from the axis of rotation to the point of uplift on the roof tile. The point of uplift shall be taken at 0.76L from the head of the tile and the middle of the exposed width. For roof tiles with nails or screws (with or without a tail clip), the axis of rotation shall be taken as the head of the tile for direct deck application or as the top edge of the batten for battened applications. For roof tiles fastened only by a nail or screw along the side of the tile, the axis of rotation shall be determined by testing. For roof tiles installed with battens and fastened only by a clip near the tail of the tile, the moment arm shall be determined about the top edge of the batten with consideration given for the point of rotation of the tiles based on straight bond or broken bond and the tile profile.

Ma = Aerodynamic uplift moment, feet-pounds (N-mm) acting to raise the tail of the tile.

qh = Wind velocity pressure, psf (kN/m2) determined from Section 6.5.10 of ASCE 7.

Concrete and clay roof tiles complying with the following limitations shall be designed to withstand the aerodynamic uplift moment as determined by this section.

  1. The roof tiles shall be either loose laid on battens, mechanically fastened, mortar set or adhesive set.
  2. The roof tiles shall be installed on solid sheathing which has been designed as components and cladding.
  3. An underlayment shall be installed in accordance with Chapter 15.27
  4. The tile shall be single lapped interlocking with a minimum head lap of not less than 2 inches (51 mm).
  5. The length of the tile shall be between 1.0 and 1.75 feet (305 mm and 533 mm).
  6. The exposed width of the tile shall be between 0.67 and 1.25 feet (204 mm and 381 mm).
  7. The maximum thickness of the tail of the tile shall not exceed 1.3 inches (33 mm).
  8. Roof tiles using mortar set or adhesive set systems shall have at least two-thirds of the tile's area free of mortar or adhesive contact.

1609.6 Alternate all-heights method. The alternate wind design provisions in this section are simplifications of the ASCE 7 Method 2—Analytical Procedure.

1609.6.1 Scope. As an alternative to ASCE 7 Section 6.5, the following provisions are permitted to be used to determine the wind effects on regularly shaped buildings, or other structures that are regularly shaped, which meet all of the following conditions:

  1. The building or other structure is less than or equal to 75 feet (22 860 mm) in height with a height-to-least-width ratio of 4 or less, or the building or other structure has a fundamental frequency greater than or equal to 1 hertz.
  2. The building or other structure is not sensitive to dynamic effects.
  3. The building or other structure is not located on a site for which channeling effects or buffeting in the wake of upwind obstructions warrant special consideration.
  4. The building shall meet the requirements of a simple diaphragm building as defined in ASCE 7 Section 6.2, where wind loads are only transmitted to the main wind-force-resisting system (MWFRS) at the diaphragms.
  5. For open buildings, multispan gable roofs, stepped roofs, sawtooth roofs, domed roofs, roofs with slopes greater than 45 degrees (0.79 rad), solid free-standing walls and solid signs, and rooftop equipment, apply ASCE 7 provisions.

1609.6.1.1 Modifications. The following modifications shall be made to certain subsections in ASCE 7: in Section 1609.6.2, symbols and notations that are specific to this section are used in conjunction with the symbols and notations in ASCE 7 Section 6.3.

1609.6.2 Symbols and notations. Coefficients and variables used in the alternative all-heights method equations are as follows:

Cnet = Net-pressure coefficient based on Kd[(G) (Cp)–(GCpi)], in accordance with Table 1609.6.2(2).

G = Gust effect factor for rigid structures in accordance with ASCE 7 Section 6.5.8.1.

Kd = Wind directionality factor in accordance with ASCE 7 Table 6-4.

Pnet = Design wind pressure to be used in determination of wind loads on buildings or other structures or their components and cladding, in psf (kN/m2).

qs = Wind stagnation pressure in psf (kN/m2) in accordance with Table 1609.6.2(1).

1609.6.3 Design equations. When using the alternative all-heights method, the MWFRS, and components and cladding of every structure shall be designed to resist the effects of wind pressures on the building envelope in accordance with Equation 16-34.

Image

Design wind forces for the MWFRS shall not be less than 10 psf (0.48 kN/m2) multiplied by the area of the structure projected on a plane normal to the assumed wind direction (see ASCE 7 Section 6.1.4 for criteria). Design net wind pressure for components and cladding shall not be less than 10 psf (0.48 kN/m2) acting in either direction normal to the surface.

1609.6.4 Design procedure. The MWFRS and the components and cladding of every building or other structure shall be designed for the pressures calculated using Equation16-34.

1609.6.4.1 Main wind-force-resisting systems. The MWFRS shall be investigated for the torsional effects identified in ASCE 7 Figure 6-9.

1609.6.4.2 Determination of Kz and Kzt. Velocity pressure exposure coefficient, Kzt shall be determined in accordance with ASCE 7 Section 6.5.6.6 and the topographic factor, Kzt shall be determined in accordance with ASCE 7 Section 6.5.7.

  1. For the windward side of a structure, Kzt and Kz shall be based on height z.
  2. For leeward and sidewalls, and for windward and leeward roofs, Kzt and Kz shall be based on mean roof height h.
TABLE 1609.6.2(1)
WIND VELOCITY PRESSURE (qs) AT STANDARD HEIGHT OF 33 FEETa
BASIC WIND SPEED (mph) 85 90 100 105 110 120 125 130 140 150 160 170
PRESSURE, qs(psf) 18.5 20.7 25.6 28.2 31.0 36.9 40.0 43.3 50.2 57.6 65.5 74.0
For SI: 1 foot = 304.8 mm, 1 mph = 0.44 m/s, 1 psf = 47.88 Pa.
a. For basic wind speeds not shown, use qs=0.00256 V2.
TABLE 1609.6.2(2)
NET PRESSURE COEFFICIENTS, Cneta,b
STRUCTURE OR PART THEREOF DESCRIPTION CnetFACTOR
1. Main wind- force-resisting frames and systems Walls: Enclosed Partially enclosed
± Internal pressure - Internal pressure ±Internal pressure - Internal pressure
Windward wall 0.43 0.73 0.11 1.05
Leeward wall -0.51 -0.21 -0.83 0.11
Sidewall -0.66 -0.35 -0.97 -0.04
Parapet wall Windward 1.28 1.28
Leeward -0.85 -0.85
Roofs: Enclosed Partially enclosed
Wind perpendicular to ridge ±Internal pressure -Internal pressure ±Internal pressure -Internal pressure
Leeward roof or flat roof -0.66 -0.35 -0.97 -0.04
Windward roof slopes:
Slope 2:12(10°) Condition 1 -1.09 -0.79 -1.41 -0.47
Condition 2 -0.28 0.02 -0.60 0.34
Slope=4:12(18°) Condition 1 -0.73 -0.42 -1.04 -0.11
Condition 2 -0.05 0.25 -0.37 0.57
Slope=5:12 (23°) Condition 1 -0.58 -0.28 -0.90 0.04
Condition 2 0.03 0.34 -0.29 0.65
Slope=6:12(27°) Condition 1 -0.47 -0.16 -0.78 0.15
Condition 2 0.06 0.37 -0.25 0.68
Slope=7:12(30°) Condition 1 -0.37 -0.06 -0.68 0.25
Condition 2 0.07 0.37 -0.25 0.69
Slope 9:12 (37°) Condition 1 -0.27 0.04 -0.58 0.35
Condition 2 0.14 0.44 -0.18 0.76
Slope 12:12 (45°) 0.14 0.44 -0.18 0.76
Wind parallel to ridge and flat roofs -1.09 -0.79 -1.41 -0.47
Nonbuilding Structures: Chimneys, Tanks and Similar Structures:
  h/D
1 7 25
Square (Wind normal to face) 0.99 1.07 1.53
Square (Wind on diagonal) 0.77 0.84 1.15
Hexagonal or Octagonal 0.81 0.97 1.13
Round 0.65 0.81 0.97
Open signs and lattice frameworks Ratio of solid to gross area
  <0.1 0.1 to 0.29 0.3 to 0.7
Flat 1.45 1.30 1.16
Round 0.87 0.94 1.08
2. Components and cladding not in areas of discontinuity— roofs and overhangs Roof elements and slopes Enclosed Partially enclosed
Gable or hipped configurations (Zone 1)
Flat < Slope < 6:12 (27°) See ASCE 7 Figure 6-11C Zone 1)
Positive 10 square feet or less 0.58 0.89
100 square feet or more 0.41 0.72
Negative 10 square feet or less -1.00 -1.32
100 square feet or more -0.92 -1.23
Overhang: Flat < Slope < 6:12(27°) See ASCE 7 Figure 6-11B Zone 1
Negative 10 square feet or less -1.45
100 square feet or more -1.36
500 square feet or more -0.94
6:12(27°) < Slope < 12:12(45°) See ASCE 7 Figure 6-11D Zone 1
Positive 10 square feet or less 0.92 1.23
100 square feet or more 0.83 1.15
Negative 10 square feet or less -1.00 -1.32
100 square feet or more -0.83 -1.15
Monosloped configurations (Zone 1) Enclosed Partially enclosed
Flat < Slope < 7:12 (30°) See ASCE 7 Figure 6-14B Zone 1
Positive 10 square feet or less 0.49 0.81
100 square feet or more 0.41 0.72
Negative 10 square feet or less -1.26 -1.57
100 square feet or more -1.09 -1.40
Tall flat-topped roofs h ≥ 60' Enclosed Partially enclosed
Flat < Slope < 2:12(10°) (Zone 1) See ASCE 7 Figure 6-17 Zone 1
Negative 10 square feet or less -1.34 -1.66
500 square feet or more -0.92 -1.23
3. Components and clading in areas of dis- continuities—roofs and overhangs Roof elements and slopes Enclosed Partially enclosed
Gable or hipped configurations at ridges, eaves and rakes (Zone 2)
Flat< Slope < 6:12 (27°) See ASCE 7 Figure 6-11C Zone 2
Positive 10 square feet or less 0.58 0.89
100 square feet or more 0.41 10.72
Negative 10 square feet or less -1.68 -2.00
100 square feet or more -1.17 -1.49
Overhang for Slope Flat< Slope< 6:12 (27°) See ASCE 7 Figure 6-11 Zone 2
Negative 10 square feet or less -1.87
100 square feet or more -1.87
6:12(27°)<Slope< 12:12(45°) Figure 6-11 D Enclosed Partially enclosed
Positive 10 square feet or less 0.92 1.23
100 square feet or more 0.83 1.15
Negative 10 square feet or less -1.17 -1.49
100 square feet or more -1.00 -1.32
Overhang for 6:12(27°)<Slope<12:12(45°) See ASCE 7 Figure 6-11 D Zone 2
Negative 10 square feet or less -1.70
500 square feet or more -1.53
Monosloped configurations at ridges, eaves and rakes (Zone 2)
Flat<Slope < 7:12 (30°) See ASCE 7 Figure 6-14B Zone 2
Positive 10 square feet or less 0.49 0.81
100 square feet or more 0.41 0.72
Negative 10 square feet or less -1.51 -1.83
100 square feet or more -1.43 -1.74
Tall flat topped roofs h>60′ Enclosed Partially enclosed
Flat<Slope<2:12(10°)(Zone 2) See ASCE 7 Figure 6-17 Zone 2
Negative 10 square feet or less -2.11 -2.42
500 square feet or more -1.51 -1.83
Gable or hipped configurations at corners (Zone 3) See ASCE 7 Figure 6-11C Zone 3
Flat<Slope<6:12(27°) Enclosed Partially enclosed
Positive 10 square feet or less 0.58 0.89
100 square feet or more 0.41 0.72
Negative 10 square feet or less -2.53 -2.85
100 square feet or more -1.85 -2.17
Overhang for Slope Flat<Slope<6:12(27°) See ASCE 7 Figure 6-11C Zone 3
Negative 10 square feet or less -3.15
100 square feet or more -2.13
6:12 (27°) < 12:12 (45°) See ASCE 7 Figure 6-11D Zone 3
Positive 10 square feet or less 0.92 1.23
100square feet or more 0.83 1.15
Negative 10 square feet or less -1.17 -1.49
100 square feet or more -1.00 -1.32
Overhang for 6:12 (27°) < Slope < 12:12 (45°) Enclosed Partially enclosed
Negative 10 square feet or less -1.70
100 square feet or more -1.53
Monosloped Configurations at corners (Zone 3) See ASCE 7 Figure 6-14B Zone 3
Flat < Slope < 7:12(30°)
Positive 10 square feet or less 0.49 0.81
100 square feet or more 0.41 0.72
Negative 10 square feet or less -2.62 -2.93
100 square feet or more -1.85 -2.17
Tall flat topped roofs h> 60′ Enclosed Partially enclosed
Flat< Slope <2:12(10°)(Zone 3) See ASCE 7 Figure 6-17 Zone 3
Negative 10 square feet or less -2.87 -3.19
500 square feet or more -2.11 -2.42
4.Components and cladding not in areas of discontinuity—walls and parapets Wall Elements: h=60′ (Zone 4) Figure 6-11A Enclosed Partially enclosed
Positive 10 square feet or less 1.00 1.32
500 square feet or more 0.75 1.06
Negative 10 square feet or less -1.09 -1.40
500 square feet or more -0.83 -1.15
Wall Elements: h=60′ (Zone 4) See ASCE 7 Figure 6-17 Zone 4
Positive 20 square feet or less 0.92 1.23
500 square feet or more 0.66 0.98
Negative 20 square feet or less -0.92 -1.23
500 square feet or more -0.75 -1.06
Parapet Walls
Positive 2.87 3.19
Negative -1.68 -2.00
5. Components and cladding in areas of discontinuity— walls and parapets Wall elements: h≤60′(Zone 5) Figure 6-11A Enclosed Partially enclosed
Positive 10 square feet or less 1.00 1.32
500 square feet or more 0.75 1.06
Negative 10 square feet or less -1.34 -1.66
500 square feet or more -0.83 -1.15
Wall elements: h>60′(Zone 5) See ASCE 7 Figure 6-17 Zone 4
Positive 20 square feet or less 0.92 1.23
500 square feet or more 0.66 0.98
Negative 20 square feet or less -1.68 -2.00
500 square feet or more -1.00 -1.32
Parapet walls
Positive 3.64 3.95
Negative -2.45 -2.76
For SI: 1 foot=304.8 mm, 1 square foot=0.029m21 degree=0.0175 rad.
a. Linear interpolation between values in the table is permitted.
b. Some Cnetnet values have been grouped together. Less conservative results may be obtained by applying ASCE 7 provisions.
31 32

1609.6.4.3 Determination of net pressure coefficients, Cnet. For the design of the MWFRS and for components and cladding, the sum of the internal and external net pressure shall be based on the net pressure coefficient, Cnet

  1. The pressure coefficient, Cnet for walls and roofs shall be determined from Table 1609.6.2(2).
  2. Where Cnet has more than one value, the more severe wind load condition shall be used for design.

1609.6.4.4 Application of wind pressures. When using the alternative all-heights method, wind pressures shall be applied simultaneously on, and in a direction normal to, all building envelope wall and roof surfaces.

1609.6.4.4.1 Components and cladding. Wind pressure for each component or cladding element is applied as follows using Cnet values based on the effective wind area, A, contained within the zones in areas of discontinuity of width and/or length “a,” “2a” or “4a” at: corners of roofs and walls; edge strips for ridges, rakes and eaves; or field areas on walls or roofs as indicated in figures in tables in ASCE 7 as referenced in Table 1609.6.2.(2) in accordance with the following:

  1. Calculated pressures at local discontinuities acting over specific edge strips or corner boundary areas.
  2. Include “field” (Zone 1,2 or 4, as applicable) pressures applied to areas beyond the boundaries of the areas of discontinuity.
  3. Where applicable, the calculated pressures at discontinuities (Zones 2 or 3) shall be combined with design pressures that apply specifically on rakes or eave overhangs.

SECTION 1610
SOIL LATERAL LOADS

1610.1 General. Foundation walls and retaining walls shall be designed to resist lateral soil loads. Soil loads specified in Table 1610.1 shall be used as the minimum design lateral soil loads unless determined otherwise by a geotechnical investigation in accordance with Section 1803. Foundation walls and other walls in which horizontal movement is restricted at the top shall be designed for at-rest pressure. Retaining walls free to move and rotate at the top shall be permitted to be designed for active pressure. Design lateral pressure from surcharge loads shall be added to the lateral earth pressure load. Design lateral pressure shall be increased if soils at the site are expansive. Foundation walls shall be designed to support the weight of the full hydrostatic pressure of undrained backfill unless a drainage system is installed in accordance with Sections 1805.4.2 and 1805.4.3.

Exception: Foundation walls extending not more than 8 feet (2438 mm) below grade and laterally supported at the top by flexible diaphragms shall be permitted to be designed for active pressure.

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TABLE 1610.1
LATERAL SOIL LOAD
DESCRIPTION OF BACK FILL MATERIALcUNIFIED SOIL CLASSIFICATIONDESIGN LATERAL SOIL LOADa (pound per square foot per foot of depth)
Active pressureAt-rest pressure
For SI: 1 Pound per square foot per foot of depth = 0.157 kPa/m, 1 foot = 304.8 mm.
a. Design lateral soil loads are given for most conditions for the specified soils at their optimum densities. Actual field conditions shall govern. Submerged or saturated soil pressures shall include the weight of the buoyant soil plus the hydrostatic loads.
b.Unsuitable as backfill material.
c.The definition and classification of soil materials shall be in accordance with ASTM D 2487.
Well-graded, clean gravels; gravel-sand mixesGW3060
Poorly graded clean gravels; gravel-sand mixesGP3060
Silty gravels, poorly graded gravel-sand mixesGM4060
Clayey gravels, poorly graded gravel-and-clay mixesGC4560
Well-graded, clean sands; gravelly sands;mixesSW3060
Poorly graded clean sands; sand-gravel mixesSP3060
Silty sands, poorly graded sand-silt mixesSM4560
Sand-silt clay mix with plastic finesSM-SC45100
Clayey sands, poorly graded sand-clay mixesSC60100
Inorganic silts and clayey siltsML45100
Mixture of inorganic silt and clayML-CL60100
Inorganic clays of low to medium plasticityCL60100
Organic silts and silt clays, low plasticityOLNote bNote b
Inorganic clays silts, elastic siltsMHNote bNote b
Inorganic clays of high plasticityCHNote bNote b
Organic clays and silty claysOHNote bNote b

SECTION 1611
RAIN LOADS

1611.1 Design rain loads. Each portion of a roof shall be designed to sustain the load of rainwater that will accumulate on it if the primary drainage system for that portion is blocked plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow. The design rainfall shall be based on the 100-year hourly rainfall rate indicated in Figure 1611.1 or on other rainfall rates determined from approved local weather data.

Image

For SI: R= 0.0098(ds+h)

where:

dh = Additional depth of water on the undeflected roof above the inlet of secondary drainage system at its design flow (i.e., the hydraulic head), in inches (mm).

ds= Depth of water on the undeflected roof up to the inlet of secondary drainage system when the primary drainage system is blocked (i.e., the static head), in inches (mm).

R = Rain load on the undeflected roof, in psf (kN/m2). When the phrase “undeflected roof” is used, deflections from loads (including dead loads) shall not be considered when determining the amount of rain on the roof.

1611.2 Ponding instability. For roofs with a slope less than ¼ inch per foot [1.19 degrees (0.0208 rad)], the design calculations shall include verification of adequate stiffness to preclude progressive deflection in accordance with Section 8.4 of ASCE 7.

1611.3 Controlled drainage. Roofs equipped with hardware to control the rate of drainage shall be equipped with a secondary drainage system at a higher elevation that limits accumulation of water on the roof above that elevation. Such roofs shall be designed to sustain the load of rainwater that will accumulate on them to the elevation of the secondary drainage system plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow determined from Section 1611.1. Such roofs shall also be checked for ponding instability in accordance with Section 1611.2.

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FIGURE 1611.1 100-YEAR, 1-HOUR RAINFALL (INCHES) EASTERN UNITED STATES

FIGURE 1611.1
100-YEAR, 1-HOUR RAINFALL (INCHES) EASTERN UNITED STATES

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

35

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) CENTRAL UNITED STATES

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

36

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFAL (INCHES) WESTERN UNITED STATES

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFAL (INCHES) WESTERN UNITED STATES

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

37

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) ALASKA

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) ALASKA

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

38

[P] FIGURE 1611.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) HAWAII

[P] FIGURE 1611.1—continued
100-YEAR, 1-HOUR RAINFALL (INCHES) HAWAII

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

39

SECTION 1612
FLOOD LOADS

1612.1 General. Within flood hazard areas as established in Section 1612.3, all new construction of buildings, structures and portions of buildings and structures, including substantial improvement and restoration of substantial damage to buildings and structures, shall be designed and constructed to resist the effects of flood hazards and flood loads. For buildings that are located in more than one flood hazard area, the provisions associated with the most restrictive flood hazard area shall apply.

1612.2 Definitions. The following words and terms shall, for the purposes of this section, have the meanings shown herein.

BASE FLOOD. The flood having a 1-percent chance of being equaled or exceeded in any given year.

BASE FLOOD ELEVATION. The elevation of the base flood, including wave height, relative to the National Geodetic Vertical Datum (NGVD), North American Vertical Datum (NAVD) or other datum specified on the Flood Insurance Rate Map (FIRM).

BASEMENT. The portion of a building having its floor subgrade (below ground level) on all sides.

This definition of “Basement” is limited in application to the provisions of Section 1612 (see “Basement” in Section 502.1).

DESIGN FLOOD. The flood associated with the greater of the following two areas:

  1. Area with a flood plain subject to a 1-percent or greater chance of flooding in any year; or
  2. Area designated as a flood hazard area on a community's flood hazard map, or otherwise legally designated.

DESIGN FLOOD ELEVATION. The elevation of the “design flood,” including wave height, relative to the datum specified on the community's legally designated flood hazard map. In areas designated as Zone AO, the design flood elevation shall be the elevation of the highest existing grade of the building's perimeter plus the depth number (in feet) specified on the flood hazard map. In areas designated as Zone AO where a depth number is not specified on the map, the depth number shall be taken as being equal to 2 feet (610 mm).

DRY FLOODPROOFING. A combination of design modifications that results in a building or structure, including the attendant utility and sanitary facilities, being water tight with walls substantially impermeable to the passage of water and with structural components having the capacity to resist loads as identified in ASCE 7.

EXISTING CONSTRUCTION. Any buildings and structures for which the “start of construction” commenced before the effective date of the community's first flood plain management code, ordinance or standard. “Existing construction” is also referred to as “existing structures..̵

EXISTING STRUCTURE. See “Existing construction.”

FLOOD or FLOODING. A general and temporary condition of partial or complete inundation of normally dry land from:

  1. The overflow of inland or tidal waters.
  2. The unusual and rapid accumulation or runoff of surface waters from any source.

FLOOD DAMAGE-RESISTANT MATERIALS. Any construction material capable of withstanding direct and prolonged contact with floodwaters without sustaining any damage that requires more than cosmetic repair.

FLOOD HAZARD AREA. The greater of the following two areas:

  1. The area within a flood plain subject to a 1-percent or greater chance of flooding in any year.
  2. The area designated as a flood hazard area on a community's flood hazard map, or otherwise legally designated.

FLOOD HAZARD AREA SUBJECT TO HIGH-VELOCITY WAVE ACTION. Area within the flood hazard area that is subject to high-velocity wave action, and shown on a Flood Insurance Rate Map (FIRM) or other flood hazard map as Zone V, VO, VE or V1-30.

FLOOD INSURANCE RATE MAP (FIRM). An official map of a community on which the Federal Emergency Management Agency (FEMA) has delineated both the special flood hazard areas and the risk premium zones applicable to the community.

FLOOD INSURANCE STUDY. The official report provided by the Federal Emergency Management Agency containing the Flood Insurance Rate Map (FIRM), the Flood Boundary and Floodway Map (FBFM), the water surface elevation of the base flood and supporting technical data.

FLOODWAY. The channel of the river, creek or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.

LOWEST FLOOR. The floor of the lowest enclosed area, including basement, but excluding any unfinished or flood-resistant enclosure, usable solely for vehicle parking, building access or limited storage provided that such enclosure is not built so as to render the structure in violation of this section.

SPECIAL FLOOD HAZARD AREA. The land area subject to flood hazards and shown on a Flood Insurance Rate Map or other flood hazard map as Zone A, AE, A1-30, A99, AR, AO, AH, V, VO, VE or V1-30.

START OF CONSTRUCTION. The date of issuance for new construction and substantial improvements to existing structures, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement or other improvement is within 180 days after the date of issuance. The actual start of construction means the first placement of permanent construction of a building (including a manufactured

40

home) on a site, such as the pouring of a slab or footings, installation of pilings or construction of columns.

Permanent construction does not include land preparation (such as clearing, excavation, grading or filling), the installation of streets or walkways, excavation for a basement, footings, piers or foundations, the erection of temporary forms or the installation of accessory buildings such as garages or sheds not occupied as dwelling units or not part of the main building, For a substantial improvement, the actual “start of construction” means the first alteration of any wall, ceiling, floor or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

SUBSTANTIAL DAMAGE. Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, rehabilitation, addition or improvement of a building or structure, the cost of which equal or exceeds 50 percent of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either:

  1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the building official and that are the minimum necessary to assure safe living conditions.
  2. Any alteration of a historic structure provided that the alteration will not preclude the structure's continued designation as a historic structure.

1612.3 Establishment of flood hazard areas. To establish flood hazard areas, the applicable governing authority shall adopt a flood hazard map and supporting data. The flood hazard map shall include,at a minimum,areas of special flood hazard as identified by the Federal Emergency Management Agency in an engineering report entitled “The Flood Insurance Study for [INSERT NAME OF JURISDICTION],” dated [INSERT DATE OF ISSUANCE], as amended or revised with the accompanying Flood Insurance Rate Map (FIRM) and Flood Boundary and Floodway Map (FBFM) and related supporting data along with any revisions thereto. The adopted flood hazard map and supporting data are hereby adopted by reference and declared to be part of this section.

Exception: [OSHPD 2] The flood hazard map shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency's Flood Insurance Study (FIS) adopted by the local authority having jurisdiction where the project is located.

1612.3.1 Design flood elevations. Where design flood elevations are not included in the flood hazard areas established in Section 1612.3, or where floodways are not designated, the building official is authorized to require the applicant to:

  1. Obtain and reasonably utilize any design flood elevation and floodway data available from a federal, state or other source; or
  2. Determine the design flood elevation and⁄or floodway in accordance with accepted hydrologic and hydraulic engineering practices used to define special flood hazard areas. Determinations shall be undertaken by a registered design professional who shall document that the technical methods used reflect currently accepted engineering practice.

1612.3.2 Determination of impacts. In riverine flood hazard areas where design flood elevations are specified but floodways have not been designated, the applicant shall provide a floodway analysis that demonstrates that the proposed work will not increase the design flood elevation more than 1 foot (305 mm) at any point within the jurisdiction of the applicable governing authority.

1612.4 Design and construction. The design and construction of buildings and structures located in flood hazard areas, including flood hazard area subject to high-velocity wave action, shall be in accordance with Chapter 5 of ASCE 7 and With ASCE 24.

1612.5 Flood hazard documentation. The following documentation shall be prepared and sealed by a registered design professional and submitted to the building official:

  1. For construction in flood hazard areas not subject to high-velocity wave action:
    1. The Elevation of the lowest floor, including the basement, as required by the lowest floor elevation inspection in Section 110.3.3, Chapter1, Division II.
    2. For fully enclosed areas below the design flood elevation where provisions to allow for the automatic entry and exit of flood waters do not meet the minimum requirements in Section 2.6.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.6.2.2 of ASCE 24.
    3. For dry floodproofed nonresidential buildings, construction documents shall include a statement that the dry floodproofing is designed in accordance with ASCE 24.
  2. For construction in flood hazard areas subject to high-velocity wave action:
    1. The elevation of the bottom of the owest horizontal structural member as required by the lowest floor elevation inspection in Section 110.3.3, Chapter 1, Division II.
    2. Construction documents shall include a statement that the building is designed in accordance with ASCE 24, including that the pile or column foundation and building or structure to be attached thereto is designed to be anchored to resist flotation, collapse and lateral movement due to the effects of wind and flood loads acting simultaneously on all building components, and other load requirements of Chapter 16. 41
    3. For breakaway walls designed to resist a nominal load of less than 10 psf (0.48 kN⁄m2) or more than 20 psf (0.96 kN⁄m2), construction documents shall include a statement that the breakaway wall is designed in accordance with ASCE 24.

SECTION 1613
EARTHQUAKE LOADS

1613.1 Scope. Every structure, and portion thereof, including nonstructural components that are permanently attached to structures and their supports and attachments, shall be designed and constructed to resist the effects of earthquake motions in accordance with ASCE 7, excluding Chapter 14 and Appendix 11A. The seismic design category for a structure is permitted to be determined in accordance with Section 1613 or ASCE 7.

Exceptions:

  1. Detached one- and two- family dwellings, assigned to Seismic Design Category A, B or C, or located where the mapped short-period spectral response acceleration, Ss, is less than 0.4 g.
  2. The seismic-force-resisting system of wood-frame buildings that conform to the provisions of Section 2308 are not required to be analyzed as specified in this section. [OSHPD 2] Not Permitted by OSHPD, see Section 2308.
  3. Agricultural storage structures intended only for incidental human occupancy.
  4. Structures that require special consideration of their response characteristics and environment that are not addressed by this code or ASCE 7 and for which other regulations provide seismic criteria, such as vehicular bridges, electrical transmission towers, hydraulic structures, buried utility lines and their appurtenances and nuclear reactors.
  5. [OSHPD 2] Seismic Design Category shall be in accordance with exception to Section 161.3.5.6.

1613.1.1 Scope, [SL] For application listed in Section 1.12 regulated by the State Librarian, only the provisions of ASCE 7 Table 13.5-1 and Table 1607.1, as amended, of this code shall apply.

1613.1.2 State-owned buildings. State-owned buildings, including those of the University of California, CSU and Judicial Council, shall not be constructed where any portion of the foundation would be within a mapped area of earthquake-induced liquefaction of landsliding or within 50 feet of a mapped fault rupture hazard as established by Section 1802.7.

1613.2 Definitions. The following words and terms shall, for the purposes of this section, have the meanings shown herein.

DESIGN EARTHQUAKE GROUND MOTION. The earthquake ground motion that buildings and structures are specifically proportioned to resist in Section 1613.

MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION. The most severe earthquake effects considered by this code.

MECHANICAL SYSTEMS. For the purposes of determining seismic loads in ASCE 7, mechanical systems shall include plumbing systems as specified therein.

ORTHOGONAL. To be in two horizontal directions, at 90 degree (1.57 rad) to each other.

SEISMIC DESIGN CATEGORY. A classification assigned to a structure based on its occupancy category and the severity of the design earthquake ground motion at the site.

SITE CLASS. A classification assigned to a site based on the types of soils present and their engineering properties as defined in section 1613.5.2.

SITE COEFFICIENTS. The values of Fa and Fv indicated in Tables 1613.5.3(1) and 1613.5.3(2), respectively.

1613.3 Existing buildings.Additions, alterations, repairs or change of occupancy category of existing buildings shall be in accordance with Chapter 34.

1613.3.1 Existing state buildings. Additions, alterations, repairs or change of occupancy category of existing buildings shall be in accordance with Chapter 34.

1613.4 Special inspections. Where required by Sections 1705.3 through 1705.3.5, the statement of special inspections shall include the special inspections required by Section 1705.3.6.

1613.5 Seismic ground motion values. Seismic ground motion values shall be determined in accordance with this section.

1613.5.1 Mapped acceleration parameters. The parameters Ss and S1 Shall be determined from the 0.2 and 1-second spectral response accelerations shown of Figures 1613.5(1) through 1613.5(14). Where S1 is less than or equal to 0.04 and Ss is less than or equal to 0.15, the structure is permitted to be assigned to Seismic Design Category A.

Exception: [OSHPD 2] Seismic Design Category shall in accordance with exception to Section 1613.5.6.

1613.5.2 Site class definitions. Based on the site soil properties, the site shall be classified as either Site class A, B, C, D, E or F in accordance with Table 1613.5.2. When the soil properties are not known in sufficient detail to determine the site class, Site Class D shall be used unless the building official or geotechnical data determines that Site Class E or F soil is likely to be present at the site.

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TABLE 1613.5.2
SITE CLASS DEFINITIONS
SITE CLASSSOIL PROFILE NAMEAVERAGE PROPERTIES IN TOP 100 feet, SEE SECTION 1613.5.5
Soil shear wave velocity, v¯s, (ft⁄s)Standard penetration resistance, N¯Soil undrained shear strength, s¯u, (psf)
a. Use straight-line interpolation for intermediate values of mapped spectral response acceleration at short period, Ss.
b. Values shall be determined in accordance with Section 11.4.7 of ASCE 7.
AHard rockv¯s > 5,000N⁄AN⁄A
BRock2,500 < v¯s≤ 5,000N⁄AN⁄A
CVery dense soil and soft rock1,200 <v¯s≤ 2,500N¯> 50S¯u≥2,000
DStiff soil profile600 ≤ v¯s 1,20015≤ N¯≤ 501,000 ≤S¯u ≤2,000
ESoft soil profileV¯s < 600N¯ < 15S¯u 1,000
E —Any profile with more than 10 feet of soil having the following characteristics:
  1. Plasticity index PI >20,
  2. Moisture content w≥40%, and
  3. Undrained shear strength S¯u<500 psf
F—Any profile containing soils having one or more of the following characteristics:
  1. Soils Vulnerable to potential failure or collapse under seismic loading such as liquefiable
    soils, quick and highly sensitive clays, collapsible weakly cemented soils.
  2. Peats and⁄or highly organic clays(H> 10 feet of peat and⁄or highly organic clay where
    H=thickness of soil)
  3. Very high plasticity clays (H>25 feet with plasticity index PI>75)
  4. Very thick soft⁄medium stiff clays (H>120 feet)
TABLE 1613.5.3(1) VALUES OF SITE COEFFICIENT Faa
SITE CLASS MAPPED SPECTRAL RESPONSE ACCELERATION AT SHORT PERIOD
Ss ≤ 0.25Ss =0.50Ss =0.75Ss =1.00Ss ≥1.25
A0.80.80.80.80.8
B1.01.01.01.01.0
C1.21.21.11.01.0
D1.61.41.21.11.0
E2.51.71.20.90.9
FNote bNote bNote bNote bNote b
TABLE 1613.5.3(2)
VALUES OF SITE COEFFICIENT Fva
SITE CLASSMAPPED SPECTRAL RESPONSE ACCELERATION AT 1-SECOND PERIOD
s1≤ 0.1s1=0.2s1=0.3s1 =0.4s1 ≥0.5
a. Use straight-line interpolation for intermediate values of mapped spectral response acceleration at 1-second period, Ss.
b. Values shall be determined in accordance with Section 11.4.7. of ASCE 7.
A0.80.80.80.80.8
B1.01.01.01.01.0
C1.71.61.51.41.3
D2.42.01.81.61.5
E3.53.22.82.42.4
FNote bNote bNote bNote bNote b
43

1613.5.3 Site coefficients and adjusted maximum considered earthquake spectral response acceleration parameters. The maximum considered earthquake spectral response acceleration for short periods, SMS, and at 1-second period, SM1, adjusted for site class effects shall be determined by Equations 16-36 and 16-37, respectively:

Image

Where:

Fa = Site coefficient defined in Table 1613.5.3(1).

Fv = Site Coefficient defined in Table 1613.5.3(2).

Ss = The mapped spectral accelerations for short periods as determined in Section 1613.5.1.

S1 =The mapped spectral accelerations for a 1-second period as determined in Section 1613.5.1.

1613.5.4 Design spectral response acceleration parameters. Five-percent damped design spectral response acceleration at short periods, Sds, shall be determined from Equation 16-38 and 16-39, respectively:

Image

where:

SMS = The maximum considered earthquake spectral response accelerations for short period as determined in Section 1613.5.3.

SM1 = The maximum considered earthquake spectral response accelerations for 1-second period as determined in Section 1613.5.3.

1613.5.5 Site Classification for seismic design. Site classification for Site Class C, D or E shall be determined from Table 1613.5.5.

The notations presented below apply to the upper 100 feet (30 480 mm) of the site profile. Profiles containing distinctly different soil and⁄or rock layer shall be subdivided into those layer designated by a number that ranges from 1 to n at the bottom where there is a total of n distinct layers in the upper 100 feet (30 480 mm). The symbol i then refers to any one of the layers between 1 and n.

Where:

Vsi = The shear wave velocity in feet per second (m⁄s).

di = The thickness of any layer between 0 and 100 feet (30 480 mm).

Where:

Image

Ni is the Standard Penetration Resistance (ASTM D 1586) not to exceed 100 blows⁄foot (328 blows⁄m) as directly measured in the field without corrections. When refusal is met for a rock layer, Ni shall be taken as 100 blows⁄foot (328 blows⁄m).

Image

Where Ni and di in Equation 16-41 are for cohesion less soil, cohesive soil and rock layers.

Image

Where:

Image

Use di and Ni for cohesion less soil layers only in Equation 16-42.

ds = The total thickness of cohesion less soil layers in the top 100 feet (30 480 mm).

m = The number of cohesionless soil layers in the top 100 feet (30 480 mm).

TABLE 1613.5.5
SITE CLASSIFICATIONa
SITE CLASSV¯sN¯ or N¯chS¯u
For SI: 1 foot per second= 304.8 mm per second, 1 pound per square Foot = (0.0479 kN⁄m2.
a. If the S¯u method is used and the N¯ch and S¯u criteria differ, select the category with the softer soils (for example, use Site Class E instead of D).
E<600 ft⁄s< 15< 1,000 psf
D600 to 1,200 ft⁄s15 to 501,000 to 2,000 psf
C1,200 to 2,500 ft⁄s>50> 2,000
44

Sui = The undrained shear strength in psf (kPa), not to exceed 5,000 psf (240 kPa), ASTM D 2166 or D 2850.

Image

Where:

Image

dc = The total thickness of cohesive soil layers in the top 100 feet (30 480 mm).

k = The number of cohesive soil layers in the top 100 feet (30 480 mm).

PI = The plasticity index, ASTM D 4318.

w = The moisture content in percent, ASTM D 2216.

Where a site does not qualify under the criteria for Site Class F and there is a total thickness of soft clay greater than 10 feet (3048 mm) where a soft clay layer is defined by: S¯u < 500 psf (24kPa), w≥40 percent, and PI > 20, it shall be classified as Site Class E.

The shear wave velocity for rock, Site Class B, shall be either measured on site or estimated by a geotechnical engineer or engineering geologist⁄seismologist for competent rock with moderate fracturing and weathering. Softer and more highly fractured and weathered rock shall either be measured on site for shear wave velocity or classified as Site Class C.

The hard rock category,Site Class A, Shall be supported by shear wave velocity measurements either on site or on profile of the same rock type in the same formation with an equal or greater degree of weathering and fracturing. Where hard rock conditions are known to be continuous to a depth of 100 feet (30 480 mm), surficial shear wave velocity measurements are permitted to be extrapolated to assess V¯s.

The rock categories, Site Classes A and B, shall not be used if there is more than 10 feet (3048 mm) of soil between the rock surface and the bottom of the spread footing or mat foundation.

1613.5.5.1 Steps for classifying a site.

  1. Check for the four categories of Site Class F requiring site-specific evaluation. If the site corresponds to any of these categories, classify the site as Site Class F and conduct a site-specific evaluation.
  2. Check for the existence of a total thickness of soft clay > 10 feet (3048 mm) where a soft clay layer is defined by: S¯u <500 psf (24 kPa), w≥ 40 percent and PI> 20. If these criteria are satisfied, classify the site as Site Class E.
  3. Categorize the site using one of the following three methods with V¯s, N¯ and S¯u and computed in all cases as specified.
    1. v¯s for the top 100 feet (30 480 mm) (v¯s method).
    2. N¯ for the top 100 feet (30 480 mm) (N¯ method).
    3. N¯ch for cohesionless soil layers (pI<20) in the top 100 feet (30 480 mm) and average, s¯u for cohesive soil layers (PI>20) in the top 100 feet (30 480 mm) (s¯u method).

1613.5.6 Determination of seismic design category.. Structures classified as Occupancy Category 1, II or III that are located where the mapped spectral response acceleration parameter at 1-second period, S1,, is greater than or equal to 0.75 shall be assigned to Seismic Design Category E. Structures classified as Occupancy Category IV that are located where the mapped spectral response acceleration parameter at 1-second period, S1,is greater than or equal to 0.75 shall be assigned to Seismic Design Category F. All other structures shall be assigned to a Seismic design category based on their occupancy category and the design spectral response acceleration coefficient, SDS and SD1,, determined in accordance with Section 1613.5.4 or the site-specific procedures of ASCE 7. Each building and structure shall be assigned to the more severe Seismic design category in accordance with Table 1613.5.6(1) or 1613.5.6(2), irrespective of the fundamental period of vibration of the structure, T.

TABLE 1613.5.6(1)
SEISMIC DESIGN CATEGORY BASED ON SHORT-PERIOD RESPONSE ACCELERATIONS
VALUE OF SDSOCCUPANCY CATEGORY
I or IIIIIIV
SDS < 0.167gAAA
0.167g≤SDS < 0.33gBBC
0.33g ≤ SDS < 0.50gCCD
0.50g≤SDSDDD
TABLE 1613.5.6(2)
SEISMIC DESIGN CATEGORY BASED ON 1-SECOND PERIOD RESPONSE ACCELERATION
VALUE OF SDSOCCUPANCY CATEGORY
I or IIIIIIV
SD1<0.067gAAA
0.067g≤SD1<0.133gBBC
0.133g≤SD1<0.20gCCD
0.20g≤SD1DDD

Exception: [OSHPD 2] Structure not assigned to seismic design category E or F above shall be assigned to seismic design category D.

1613.5.6.1 Alternative Seismic design category determination. Where S1 is less than 0.75, the seismic design

45

category is permitted to be determined from Table 1613.5.6(1) alone when all of the following apply:

  1. In each of the two orthogonal directions, the approximate fundamental period of the structure, Ta in each of the two orthogonal directions determined in accordance with Section 12.8.2.1 of ASCE 7, is less than 0.8 Τs determined in accordance with Section 11.4.5 of ASCE 7.
  2. In each of the two orthogonal directions, the fundamental period of the structure used to calculate the story drift is less than Τs
  3. Equation 12.8-2 of ASCE 7 is used to determine the scismic response coefficient, Cs.
  4. The diaphragms are rigid as defined in Section 12.3.1 of ASCE 7 or, for diaphragms that are flexible, the distances between vertical elements of the seismic-force-resisting system do not exceed 40 feet (12 192 mm).

Exception: [OSHPD 2] Seismic design category shall be determined in accordance with exception to Section 1613.5.6.

1613.5.6.2 Simplified design procedure. Where the alternate simplified design procedure of ASCE 7 is used, the seismic design category shall be determined in accordance with ASCE 7.

Exception: [OSHPD 2] Seismic design category shall be determined in accordance with exception to Section 1613.5.6.

1613.6 Alternatives to ASCE 7. The provisions of Section 1613.6 shall be permitted as alternatives to the relevant provisions of ASCE 7.

1613.6.1 Assumption of flexible diaphragm. Add the following text at the end of Section 12.3.1.1 of ASCE 7.

Diaphragms constructed of wood structural panels or untopped steel decking shall also be permitted to be idealized as flexible, provided all of the following conditions are met:

  1. Toppings of concrete or similar materials are not placed over wood structural panel diaphragms except for nonstructural toppings no greater than 1½ inches (38 mm) thick.
  2. Each line of vertical elements of the seismic-force-resisting system complies with the allowable story drift of Table 12.12-1.
  3. Vertical elements of the seismic-force-resisting system are light-frame walls sheathed with wood structural panels rated for shear resistance or steel sheets.
  4. Portions of wood structural panel diaphragms that cantilever beyond the vertical elements of the lateral-force-resisting system are designed in accordance with Section 4.2.5.2 of AF&PA SDPWS.

1613.6.2 Additional seismic-force-resisting systems for seismically isolated structures. Add the following exception to the end of Section 17.5.4.2 of ASCE 7:

Exception: For isolated structures designed in accordance with this standard, the Structural System Limitations and the Building Height Limitations in Table 12.2-1 for ordinary steel concentrically braced frames (OCBFs) as defined in Chapter 11 and ordinary moment frames (OMFs) as defined in Chapter 11 are permitted to be taken as 160 feet (48 768 mm) for structures assigned to Seismic Design Category D, E or F, provided that the following conditions are satisfied:

  1. The value of R1 as defined in Chapter 17 is taken as 1.
  2. For OMFs and OCBFs, design is in accordance with AISC 341.

1613.6.3 Automatic sprinkler systems. Automatic sprinkler systems designed and installed in accordance with NFPA 13 shall be deemed to meet the requirements of Section 13.6.8 of ASCE 7.

1613.6.4 Autoclaved aerated concrete (AAC) masonry shear wall design coefficients and system limitations. Add the following text at the end of Section 12.2.1 of ASCE 7:

For ordinary reinforced AAC masonry shear walls used in the seismic-force-resisting system of structures, the response modification factor, R, shall be permitted to be taken as 2, the deflection amplification factor, Cd, shall be permitted to be taken as 2 and the system overstrength factor, Ωo, shall be permitted to be taken as 2½. Ordinary reinforced AAC masonry shear walls shall not be limited in height for buildings assigned to Seismic Design Category B, shall be limited in height to 35 feet (10 668 mm) for buildings assigned to Seismic Design Category C and are not permitted for buildings assigned to Seismic Design Categories D, E and F.

For ordinary plain (unreinforced) AAC masonry shear walls used in the seismic-force-resisting system of structures, the response modification factor, R, shall be permitted to be taken as 1½, the deflection amplification factor, Cd, shall be permitted to be taken as 1½ and the system overstrength factor, Ωo, shall be permitted to be taken as 2½ Ordinary plain (unreinforced) AAC masonry shear walls shall not be limited in height for buildings assigned to Seismic Design Category B and are not permitted for buildings assigned to Seismic Design Categories C, D, E and F.

1613.6.5 Seismic controls for elevators. Seismic switches in accordance with Section 8.4.10 of ASME A17.1 shall be deemed to comply with Section 13.6.10.3 of ASCE 7.

1613.6.6 Steel plate shear wall height limits. Modify Section 12.2.5.4 of ASCE 7 to read as follows:

12.2.5.4 Increased building height limit for steelbraced frames, special steel plate shear walls and special reinforced concrete shear walls. The height limits in Table 12.2-1 are permitted to be increased from 160 feet (48 768 mm) to 240 feet (75 152 mm) for structures assigned to Seismic Design Category D or E and from 100 feet (30 480 mm) to 160 feet (48 768 mm) for structures assigned to Seismic Design Category F that have

46

steel-braced frames, special steel plate shear walls or special reinforced concrete cast-in-place shear walls and that meet both of the following requirements:

  1. The structure shall not have an extreme torsional irregularity as defined in Table 12.2-1 (horizontal structural irregularity Type 1b).
  2. The braced frames or shear walls in any one plane shall resist no more than 60 percent of the total seismic forces in each direction, neglecting accidental torsional effects.

1613.6.7 Minimum distance for building separation. All buildings and structures shall be separated from adjoining structures. Separations shall allow for the maximum inelastic response displacement (δM). δM shall be determined at critical locations with consideration for both translational and torsional displacements of the structure using Equation 16-44.

Image

where:

Cd = Deflection amplification factor in Table 12.2-1 of ASCE 7.

Smax = Maximum displacement defined in Section 12.8.4.3 of ASCE 7.

I = Importance factor in accordance with Section 11.5.1 of ASCE 7.

Adjacent buildings on the same property shall be separated by a distance not less than δMT, determined by Equation 16-45.

Image

where:

δM1, δM2 = The maximum inelastic response displacements of the adjacent buildings in accordance with Equation 16-44.

Where a structure adjoins a property line not common to a public way, the structure shall also be set back from the property line by not less than the maximum inelastic response displacement, δM, of that structure.

Exceptions:

  1. Smaller separations or property line setbacks shall be permitted when justified by rational analyses.
  2. Buildings and structures assigned to Seismic Design Category A, B or C.

1613.6.8 HVAC ductwork with Ip = 1.5. Seismic supports are not required for HVAC ductwork with Ip = 1.5 if either of the following conditions is met for the full length of each duct run:

  1. HVAC ducts are suspended from hangers 12 inches (305 mm) or less in length with hangers detailed to avoid significant bending of the hangers and their attachments, or
  2. HVAC ducts have a cross-sectional area of less than 6 square feet (0.557 m2).

1613.6.9 Exceptions for nonstructural components. [BSC] Replace ASCE 7 Section 13.1.3 by the following items:

Exemptions: The following nonstructural components are exempt from the requirements of this section:

  1. Furniture (except storage cabinets as noted in Table 13.5-1.
  2. Temporary or moveable equipment.
  3. Architectural components in Seismic Design Category B other than parapets supported by bearing walls or shear walls, provided that the component importance factor 1p is equal to 1.0.
  4. Mechanical and electrical components in Seismic Design Category B.
  5. Mechanical and electrical components in Seismic Design Category C, provided that the component importance factor, Ip is equal to 1.0.
  6. Mechanical and electrical components in Seismic Design Category D, E or F where all of the following apply:
    1. The component importance factor, Ip is equal to 1.0;
    2. The component is positively attached to the structure;
    3. Flexible connections are provided between the component and associated ductwork, piping and conduit; and either:
      1. The component weighs 400 lb (1780 N) or less and has a center of mass located 4 ft (1.22 m) or less above the adjacent floor level; or
      2. The component weighs 20 lb (89 N) or less, or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.

1613.6.10 Exceptions for nonstructural components. [BSC] Replace Items 4 and 5 of ASCE 7 Section 13.1.4 with the following items.

4. Mechanical and electrical components in Seismic Design Category D, E or F where all of the following apply:

  1. The component importance factor, Ip is equal to 1.0;
  2. The component is positively attached to the structure;
  3. Flexible connections are provided between the component and associated ductwork, piping and conduit; and either:
    1. The component weights 400 lb (1780 N) or less and has a center of mass located 4 ft (1.22 m) or less above adjacent floor level. 47
    2. The component weights 20 lb (89 N) or less, or, in the case of a distributed system, 5 lb/ft (73N/m) or less.

1613.7 ASCE 7, Section 11.7.5. Modify ASCE 7, Section 11.7.5 to read as follows:

11.7.5 Anchorage of walls. Walls shall be anchored to the roof and all floors and members that provide lateral support for the wall or that are supported by the wall. The anchorage shall provide a direct connection between the walls and the roof or floor construction. The connections shall be capable of resisting the forces specified in Section 11.7.3 applied horizontally, substituted for E in load combinations of Section 2.3 or 2.4.

SECTION 1614
STRUCTURAL INTEGRITY

1614.1 General. Buildings classified as high-rise buildings in accordance with Section 403 and assigned to Occupancy Category III or IV shall comply with the requirements of this section. Frame structures shall comply with the requirements of Section 1614.3. Bearing wall structures shall comply with the requirements of Section 1614.4.

1614.2 Definitions. The following words and terms shall, for the purposes of Section 1614, have the meanings shown herein.

BEARING WALL STRUCTURE. A building or other structure in which vertical loads from floors and roofs are primarily supported by walls.

FRAME STRUCTURE. A building or other structure in which vertical loads from floors and roofs are primarily supported by columns.

1614.3 Frame structures. Frame structures shall comply with the requirements of this section.

1614.3.1 Concrete frame structures. Frame structures constructed primarily of reinforced or prestressed concrete, either cast-in-place or precast, or a combination of these, shall conform to the requirements of ACI 318 Sections 7.13, 13.3.8.5, 13.3.8.6, 16.5, 18.12.6, 18.12.7 and 18.12.8 as applicable. Where ACI 318 requires that nonprestressed reinforcing or prestressing steel pass through the region bounded by the longitudinal column reinforcement, that reinforcing or prestressing steel shall have a minimum nominal tensile strength equal to two-thirds of the required one-way vertical strength of the connection of the floor or roof system to the column in each direction of beam or slab reinforcement passing through the column.

Exception: Where concrete slabs with continuous reinforcing having an area not less than 0.0015 times the concrete area in each of two orthogonal directions are present and are either monolithic with or equivalently bonded to beams, girders or columns, the longitudinal reinforcing or prestressing steel passing through the column reinforcement shall have a nominal tensile strength of one-third of the required one-way vertical strength of the connection of the floor or roof system to the column in each direction of beam or slab reinforcement passing through the column.

1614.3.2 Structural steel, open web steel joist or joist girder, or composite steel and concrete frame structures. Frame structures constructed with a structural steel frame or a frame composed of open web steel joists, joist girders with or without other structural steel elements or a frame composed of composite steel or composite steel joists and reinforced concrete elements shall conform to the requirements of this section.

1614.3.2.1 Columns. Each column splice shall have the minimum design strength in tension to transfer the design dead and live load tributary to the column between the splice and the splice or base immediately below.

1614.3.2.2 Beams. End connections of all beams and girders shall have a minimum nominal axial tensile strength equal to the required vertical shear strength for allowable stress design (ASD) or two-thirds of the required shear strength for load and resistance factor design (LRFD) but not less than 10 kips (45 kN). For the purpose of this section, the shear force and the axial tensile force need not be considered to act simultaneously.

Exception: Where beams, girders, open web joist and joist girders support a concrete slab or concrete slab on metal deck that is attached to the beam or girder with not less than 3/8-inch-diameter (9.5 mm) headed shear studs, at a spacing of not more than 12 inches (305 mm) on center, averaged over the length of the member, or other attachment having equivalent shear strength, and the slab contains continuous distributed reinforcement in each of two orthogonal directions with an area not less than 0.0015 times the concrete area, the nominal axial tension strength of the end connection shall be permitted to be taken as half the required vertical shear strength for ASD or one-third of the required shear strength for LRFD, but not less than 10 kips (45 kN).

1614.4 Bearing wall structures. Bearing wall structures shall have vertical ties in all load-bearing walls and longitudinal ties, transverse ties and perimeter ties at each floor level in accordance with this section and as shown in Figure 1614.4.

1614.4.1 Concrete wall structures. Precast bearing wall structures constructed solely of reinforced or prestressed concrete, or combinations of these shall conform to the requirements of Sections 7.13, 13.3.8.5 and 16.5 of ACI 318.

1614.4.2 Other bearing wall structures. Ties in bearing wall structures other than those covered in Section 1614.4.1 shall conform to this section.

1614.4.2.1 Longitudinal ties. Longitudinal ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Longitudinal ties shall extend across interior load-bearing walls and shall connect to exterior load-bearing walls and shall be spaced at not greater than 10 feet (3038 mm) on center. Ties shall have a minimum nominal tensile strength,

48

TT given by Equation 16-46. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

Image

where:

L = The span of the horizontal element in the direction of the tie, between bearing walls, feet (m).

w = The weight per unit area of the floor or roof in the span being tied to or across the wall, psf (N/m2).

S = The spacing between ties, feet (m).

αT= A coefficient with a value of 1,500 pounds per foot (2.25 kN/m) for masonry bearing wall structures and a value of 375 pounds per foot (0.6 kN/m) for structures with bearing walls of cold-formed steel light-frame construction.

1614.4.2.2 Transverse ties. Transverse ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Transverse ties shall be placed no farther apart than the spacing of loadbearing walls. Transverse ties shall have minimum nominal tensile strength TT given by Equation 16-46. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

1614.4.2.3 Perimeter ties. Perimeter ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Ties around the perimeter of each floor and roof shall be located within 4 feet (1219 mm) of the edge and shall provide a nominal strength in tension not less than Tp given by Equation 16-47. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

Image

For SI:

Tp = 90.7w ≤ βT

where:

w = As defined in Section 1614.4.2.1.

βT = A coefficient with a value of 16,000 pounds (7200 kN) for structures with masonry bearing walls and a value of 4,000 pounds (1300 kN) for structures with bearing walls of cold-formed steel light-frame construction.

1614.4.2.4 Vertical ties. Vertical ties shall consist of continuous or spliced reinforcing, continuous or spliced members, wall sheathing or other engineered systems. Vertical tension ties shall be provided in bearing walls and shall be continuous over the height of the building. The minimum nominal tensile strength for vertical ties within a bearing wall shall be equal to the weight of the wall within that story plus the weight of the diaphragm tributary to the wall in the story below. No fewer than two ties shall be provided for each wall. The strength of each tie need not exceed 3,000 pounds per foot (450 kN/m) of wall tributary to the tie for walls of masonry construction or 750 pounds per foot (140 kN/m) of wall tributary to the tie for walls of cold-formed steel light-frame construction.

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FIGURE 1613.5(1) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(1)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

50

FIGURE 1613.5(1)—continued MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(1)—continued
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

51

FIGURE 1613.5(2) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(2)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

52

FIGURE 1613.5(2)—continued MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(2)—continued
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR THE CONTERMINOUS UNITED STATES OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

53

FIGURE 1613.5(3) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(3)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

54

FIGURE 1613.5(3)—continued MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(3)—continued
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

55

FIGURE 1613.5(4) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(4)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF
1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

56

FIGURE 1613.5(4)—continued MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(4)—continued
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 1 OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

57

FIGURE 1613.5(5) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 2 OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

1613.5(5)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 2 OF
0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

58

FIGURE 1613.5(6) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 2 OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(6)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 2 OF
1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

59

FIGURE 1613.5(7) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 3 OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% PERCENT OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(7)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 3 OF
0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% PERCENT OF CRITICAL DAMPING), SITE CLASS B

60

FIGURE 1613.5(8) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 3 OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(8)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 3 OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

61

FIGURE 1613.5(9)MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 4 OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(9)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR REGION 4 OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

62

FIGURE 1613.5(10) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR HAWAII OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(10)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR HAWAII OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

63

FIGURE 1613.5(11)MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR ALASKA OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(11)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR ALASKA OF 0.2 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

64

FIGURE 1613.5(12) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR ALASKA OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(12)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR ALASKA OF 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

65

FIGURE 1613.5(13) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR PUERTO RICO, CULEBRA, VIEQUES, ST. THOMAS, ST. JOHN AND ST. CROIX OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(13)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR PUERTO RICO, CULEBRA, VIEQUES, ST. THOMAS, ST. JOHN AND ST. CROIX OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

66

FIGURE 1613.5(14) MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR GUAM AND TUTUILLA OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

FIGURE 1613.5(14)
MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION FOR GUAM AND TUTUILLA OF 0.2 AND 1.0 SEC SPECTRAL RESPONSE ACCELERATION (5% OF CRITICAL DAMPING), SITE CLASS B

67

FIGURE 1614.4 LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES

FIGURE 1614.4
LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES

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SECTION 1615
ADDITIONAL REQUIREMENTS [DSA-SS/CC]

1615.1 Construction documents.

1615.1.1 Additional requirements for construction documents are included in Sections 4-210 and 4-317 of the Building Standards Administrative Code (Part 1, Title 24, C.C.R).

1615.1.2 Connections. Connections that resist design seismic forces shall be designed and detailed on the design drawings.

1615.1.3 Construction procedures. Where unusual erection or construction procedures are considered essential by the project structural engineer or architect in order to accomplish the intent of the design or influence the design, such procedure shall be indicated on the plans or in the specifications.

1615.2 General design requirements.

1615.2.1 Lateral load deflections.

1615.2.1.1 Horizontal diaphragms. The maximum span-width ratio for any roof or floor diaphragm shall not exceed those given in Table 2305.2 or Table 4.2.4 of AF & PA SDPWS for wood sheathed diaphragms. For other diaphragms, test data and design calculations acceptable to the enforcement agency shall be submitted and approved for span-width ratios.

1615.2.1.2 Veneers. The deflection shall not exceed the limits in Section 1405.10 for veneered walls, anchored veneers and adhered veneers over 1 inch (25 mm) thick, including the mortar backing.

1615.2.1.3 Occupancy Category of buildings and other structures. Occupancy Category IV includes structures as defined in C.C.R. Title 24, Part 1, Section 4-207 and all structures required for their continuous operation or access/egress.

1615.3 Load combinations.

1615.3.1 Stability. When checking stability under the provisions of Section 1605.1.1 using allowable stress design, the factor of safety for soil bearing values shall not be less than the overstrength factor of the structures supported.

1615.4 Roof dead loads. The design dead load shall provide for the weight of at least one additional roof covering in addition to other applicable loadings if the new roof covering is permitted to be applied over the original roofing without its removal, in accordance with Section 1510.

1615.5 Live loads.

1615.5.1 Modifications to Table 1607.1.

1615.5.1.1 Item 4. Assembly areas and theaters. The following minimum loads for stage accessories apply:

  1. Gridirons and fly galleries: 75 pounds per square foot uniform live load.
  2. Loft block wells: 250 pounds per lineal foot vertical load and lateral load.
  3. Head block wells and sheave beams: 250 pounds per lineal foot vertical load and lateral load. Head block wells and sheave beams shall be designed for all tributary loft block well loads. Sheave blocks shall be designed with a safety factor of five.
  4. Scenery beams where there is no gridiron: 300 pounds per lineal foot vertical load and lateral load.
  5. Ceiling framing over stages shall be designed for a uniform live load of 20 pounds per square foot. For members supporting a tributary area of 200 square feet or more, this additional load may be reduced to 15 pounds per square foot (0.72 kN⁄m2).

The minimum uniform live load for a press box floor or accessible roof with railing is 100 psf.

1615.5.1.2 Item 22. Libraries. The minimum vertical design live load shall be as follows:

Paper media:

12-inch-deep (305 mm) shelf – 33 pounds per lineal foot (482 N/m)

15-inch-deep (381 mm) shelf – 41 pounds per lineal foot (598 N/m), or

33 pounds per cubic foot (5183 N/m3) per total volume of the rack or cabinet, whichever is less.

Film media:

18-inch-deep (457 mm) shelf – 100 pounds per lineal foot (1459 N/m), or

50 pounds per cubic foot (7853 N/m3) per total volume of the rack or cabinet, whichever is less.

Other media:

20 pounds per cubic foot (311 N/m3) or 20 pounds per square foot (958 Pa), whichever is less, but not less than actual loads.

1615.5.1.3 Item 25. Office buildings. The minimum vertical design live load shall conform to Section 1615.5.1.2.

1615.5.1.4 Item 28. Reviewing stands, grandstands and bleachers. The minimum uniform live load for a press box floor or accessible roof with railing is 100 psf.

1615.5.1.5 Item 40. Yards and terraces, pedestrians. Item 40 applies to pedestrian bridges and walkways that are not subjected to uncontrolled vehicle access.

1615.5.1.6 Item 41. Storage racks and wall-hung cabinets. The minimum vertical design live load shall conform to Section 1615.5.1.2.

1615.5.2 Uncovered open-frame roof structures. Uncovered open-frame roof structures shall be designed for a vertical live load of not less than 10 pounds per square foot (0.48 kN/m2) of the total area encompassed by the framework.

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1615.6 Determination of snow loads. The ground snow load or the design snow load for roofs shall conform with the adopted ordinance of the city, county, or city and county in which the project site is located, and shall be approved by DSA.

1615.7 Wind loads.

1615.7.1 Special wind regions. The basic wind speed for projects located in special wind regions as defined in Figure 1609 shall conform with the adopted ordinance of the city, county, or city and county in which the project site is located, and shall be approved by DSA-SS/CC.

1615.7.2 Story drift for wind loads. The calculated story drift due to wind pressures shall not exceed 0.005 times the story height for buildings less than 65 feet (19 812 mm) in height or 0.004 times the story height for buildings 65 feet (19 812 mm) or greater in height.

1615.8 Establishment of flood hazard areas. Flood hazard maps shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency’s Flood Insurance Study (FIS) adopted by the local authority having jurisdiction where the project is located, as amended or revised with the accompanying Flood Insurance Rate Map (FIRM) and Flood Boundary and Floodway Map (FBFM) and related supporting data along with any revisions thereto.

1615.9 Earthquake loads.

1615.9.1 Seismic design category. The seismic design category for a structure shall be determined in accordance with Section 1613.

1615.9.2 Definitions. In addition to the definitions in Section 1613.2, the following words and terms shall, for the purposes of this section, have the meanings shown herein.

ACTIVE EARTHQUAKE FAULT. A fault that has been the source of earthquakes or is recognized as a potential source of earthquakes, including those that have exhibited surface displacement within Holocene time (about 11,000 years) as determined by California Geological Survey (CGS) under the Alquist-Priolo Earthquake Fault Zoning Act, those included as type A or type B faults for the U.S. Geological Survey (USGS) National Seismic Hazard Maps, and faults considered to have been active in Holocene time by an authoritative source, federal, state or local governmental agency.

BASE. The level at which the horizontal seismic ground motions are considered to be imparted to the structure or the level at which the structure as a dynamic vibrator is supported. This level does not necessarily coincide with the ground level.

DISTANCE FROM AN ACTIVE EARTHQUAKE FAULT. Distance measured from the nearest point of the building to the closest edge of an Alquist-Priolo Earthquake fault zone for an active fault, if such a map exists, or to the closest mapped splay of the fault.

IRREGULAR STRUCTURE. A structure designed as having one or more plan or vertical irregularities per ASCE 7 Section 12.3.

NEXT GENERATION ATTENUATION (NGA). Attenuation relations used for the 2008 United States Geological Survey (USGS) seismic hazards maps (for the Western United States) or their equivalent as determined by the enforcement agency.

STRUCTURAL ELEMENTS. Floor or roof diaphragms, decking, joists, slabs, beams, or girders, columns, bearing walls, retaining walls, masonry or concrete nonbearing walls exceeding one story in height, foundations, shear walls or other lateral-force-resisting members, and any other elements necessary to the vertical and lateral strength or stability of either the building as a whole or any of its parts, including connection between such elements.

1615.9.3 Mapped acceleration parameters. Seismic Design Category shall be determined in accordance with Section 1613.5.6.

1615.9.4 Determination of seismic design category. Structures not assigned to Seismic Design Category E or F in accordance with Section 1613.5 shall be assigned to Seismic Design Category D.

1615.9.4.1 Alternative seismic design category determination. The alternative Seismic Design Category determination procedure of Section 1613.5.6.1 is not permitted by DSA-SS/CC.

1615.9.4.2 Simplified design procedure. The simplified design procedure of Section 1613.5.6.2 is not permitted by DSA-SS/CC.

1615.9.5 Automatic sprinkler systems. The allowable values for design of anchors, hangers and bracing elements shall be determined in accordance with material chapters of this code in lieu of those in NFPA 13.

1615.9.6 Anchorage of walls. The modification of ASCE 7, Section 11.7.5 in Section 1613.7 not adopted by DSA-SS/CC.

1615.10 Modifications to ASCE 7. The text of ASCE 7 shall be modified as indicated in Sections 1615.10.1 through 1615.10.26.

1615.10.1 ASCE 7, Section 11.1. Modify ASCE 7 Section 11.1 by adding Section 11.1.5 as follows:

11.1.5 Structural design criteria. Where design reviews are required in ASCE 7, Chapters 16, 17 or 18, the ground motion, analysis and design methods, material assumptions and acceptance criteria proposed by the engineer shall be submitted to the enforcement agency in the form of structural design criteria for approval.

1615.10.2 ASCE 7, Section 11.4.7. Modify ASCE 7 Section 11.4.7 as follows:

11.4.7 Site-specific ground motion procedures. The site-specific ground motion procedure set forth in ASCE 7 Chapter 21 as modified in Section 1803A.6 of this code is permitted to be used to determine ground motion for any structure.

Unless otherwise approved, the site-specific procedure per ASCE 7 Chapter 21 as modified by Section.

70

1803A.6 of this code shall be used where any of the following conditions apply:

  1. A site response analysis shall be performed per Section 21.1 and a ground motion hazard analysis shall be performed in accordance with Section 21.2 for the following structures:
    1. Structure located in Type E soils and mapped MCE spectral acceleration at short periods (Ss) exceeds 2.0g.
    2. Structures located in Type F soils.

      Exception:

      1. Where Ss is less than 0.20g, use of Type E soil profile shall be permitted.
      2. Where exception to Section 20.3.1 is applicable except for base isolated buildings.
  2. A ground motion hazard analysis shall be performed in accordance with Section 21.2 when:
    1. A time history response analysis of the building is performed as part of the design.
    2. The building site is located in an area identified in Section 4-317(e) of the California Administrative Code (Part 1, Title 24, C.C.R).
    3. For seismically isolated structures and for structures with damping systems.

1615.10.3 ASCE 7, Table 12.2-1. Modify ASCE 7 Table 12.2 -1 as follows:

  1. BEARING WALL SYSTEMS

    14. Light-framed walls with shear panels of all other materials – Not permitted by DSA-SS/CC.

  2. BUILDING FRAME SYSTEMS

    24. Light-framed walls with shear panels of all other materials – Not permitted by DSA-SS/CC.

Exception:

  1. Systems listed in this section can be used as an alternative system when pre-approved by the enforcement agency.
  2. Rooftop or other supported structures not exceeding two stories in height and 10 percent of the total structure weight can use the systems in this section when designed as components per ASCE 7 Chapter 13.
  3. Systems listed in this section can be used for seismically isolated buildings when permitted by Section 1613.6.2.

1615.10.4 ASCE 7, Section 12.2.3.1. Modify ASCE 7 Section 12.2.3.1 by adding the following additional requirements for a two stage equivalent lateral force procedure or modal response spectrum procedure:

e. Where design of elements of the upper portion is governed by special seismic load combinations, the special loads shall be considered in the design of the lower portions.

1615.10.5 ASCE 7, Section 12.3.3. Modify ASCE 7 Section 12.3.3.1 as follows:

12.3.3.1 Prohibited horizontal and vertical irregularities for Seismic Design Categories D through F. Structures assigned to Seismic Design Category E or F having horizontal structural irregularity Type 1b of Table 12.3-1 or vertical structural irregularities Type 1b, 5a or 5b of Table 12.3-2 shall not be permitted. Structures assigned to Seismic Design Category D having vertical irregularity Type 1b or 5b of Table 12.3-2 shall not be permitted.

1615.10.6 ASCE 7, Section 12.7.2 Modify ASCE 7 Section 12.7.2 by adding Item 5 to read as follows:

5. Where buildings provide lateral support for walls retaining earth, and the exterior grades on opposite sides of the building differ by more than 6 feet (1829 mm), the load combination of the seismic increment of earth pressure due to earthquake acting on the higher side, as determined by a Geotechnical engineer qualified in soils engineering, plus the difference in earth pressures shall be added to the lateral forces provided in this section.

1615.10.7 ASCE 7, Section 12.8.7. Modify ASCE 7 Section 12.8.7 by replacing Equation 12.8-16 as follows:

Image

1615.10.8 ASCE 7, Section 12.9.4. Replace ASCE 7 Section 12.9.4 as follows:

12.9.4 Scaling design values of combined response. Modal base shear shall not be less than the base shear calculated using the equivalent lateral force procedure of Section 12.8.

16.15.10.9 ASCE 7, Section 12.13.1. Modify ASCE 7 Section 12.13.1 by adding Section 12.13.1.1 as follows:

12.13.1.1 Foundations and superstructure-to-foundation connections. The foundation shall be capable of transmitting the design base shear and the overturning forces from the structure into the supporting soil. Stability against overturning and sliding shall be in accordance with Section 1605.1.1.

In addition, the foundation and the connection of the superstructure elements to the foundation shall have the strength to resist, in addition to gravity loads, the lesser of the following seismic loads:

  1. The strength of the superstructure elements 71
  2. The maximum forces that would occur in the fully yielded structural system
  3. Forces from the Load Combinations with overstrength factor in accordance with ASCE 7 Section 12.4.3.2

Exceptions:

  1. Where referenced standards specify the use of higher design loads.
  2. When it can be demonstrated that inelastic deformation of the foundation and superstructure-to-foundation connection will not result in a weak story or cause collapse of the structure.
  3. Where basic structural system consists of light-framed walls with shear panels.

Where the computation of the seismic overturning moment is by the equivalent lateral-force method or the modal analysis method, reduction in overturning moment permitted by Section 12.13.4 of ASCE 7 may be used.

Where moment resistance is assumed at the base of the superstructure elements, the rotation and flexural deformation of the foundation as well as deformation of the superstructure-to-foundation connection shall be considered in the drift and deformation compatibility analyses.

1615.10.10 ASCE 7, Section 13.1.4. Replace ASCE 7 Section 13.1.4 by the following:

13.1.4 Exemptions. The following nonstructural components are exempt from the requirements of this section:

  1. Furniture (except storage cabinets as noted in Table 13.5-1).
  2. Temporary or moveable equipment.

    Exceptions:

    1. Equipment shall be anchored if it is permanently attached to the building utility services such as electricity, gas, or water. For the purposes of this requirement, “permanently attached” shall include all electrical connections except three-prong plugs for duplex receptacles.
    2. The enforcement agency shall be permitted to require temporary attachments for movable equipment which is usually stationed in one place and heavier than 400 pounds, when they are not in use for a period longer than 8 hours at a time.
  3. Mechanical and electrical components in Seismic Design Categories D, E or F where all of the following apply:
    1. The component is positively attached to the structure;
    2. Flexible connections are provided between the component and associated ductwork, piping and conduit; and either:
      1. The component weighs 400 lb (1780 N) or less and has a center of mass located 4 ft (1.22 m) or less above the adjacent floor or roof level;

        Exception: Special Certification Requirements for Designated Seismic Systems in accordance with Section 13.2.2 shall apply.

        or

      2. The component weighs 20 lb (89 N) or less or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.

        Exception: The enforcement agency shall be permitted to require attachments for equipment with hazardous contents to be shown on construction documents irrespective of weight.

1615.10.11 ASCE 7, Section 13.3.2. Modify ASCE 7 Section 13.3.2 by adding the following:

The seismic relative displacements to be used in design of displacement sensitive nonstructural components is Dp I instead of Dp’where Db is given by Equations 13.3-5 to 13.3-8 and I is the building importance factor given in Section 11.5.

1615.10.12 ASCE 7, Section 13.4.5. Replace ASCE 7 Section 13.4.5 by the following:

13.4.5 Power actuated fasteners. Power actuated fasteners in concrete shall not be used for gravity tension loads exceeding 100 lb (445 N) in Seismic Design Categories D, E or F unless approved for seismic loading. Power actuated fasteners in steel are permitted in Seismic Design Category D, E or F if the gravity tension load on any fastener does not exceed 250 lbs (1123 N) unless approved for seismic loading. Power actuated fasteners in masonry are not permitted unless approved for seismic loading.

1615.10.13 ASCE 7, Section 13.5.6. Replace ASCE 7, Section 13.5.6 by the following:

13.5.6 Suspended ceilings. Suspended ceilings shall be in accordance with this section.

13.5.6.1 Seismic forces. The weight of the ceiling, Wp, shall include the ceiling grid; ceiling tiles or panels; light fixtures if attached to, clipped to, or laterally supported by the ceiling grid; and other components that are laterally supported by the ceiling. Wp shall be taken as not less than 4 psf (19 N/m2).

The seismic force, Fp’ shall be transmitted through the ceiling attachments to the building structural elements or the ceiling-structure boundary.

13.5.6.2 Industry standard construction for acoustical tile or lay-in panel ceilings. Unless designed in accordance with ASTM E 580 Section 5.2.8.8, or seismically qualified in accordance with Sections 13.2.5 or 13.2.6,

72

acoustical tile or lay-in panel ceilings shall be designed and constructed in accordance with this section.

13.5.6.2.1 Seismic Design Categories D through F. Acoustical tile or lay-in panel ceilings in Seismic Design Categories D, E and F shall be designed and installed in accordance with ASTM C 635, ASTM C 636, and ASTM E 580, Section 5 - Seismic Design Categories D, E and F as modified by this section.

13.5.6.2.2 Modification to ASTM E 580. Modify ASTM E 580 by the following:

  1. Exitways. Lay-in ceiling assemblies in exitways of hospitals and essential services buildings shall be installed with a main runner or cross runner surrounding all sides of each piece of tile, board or panel and each light fixture or grille. A cross runner that supports another cross runner shall be considered as a main runner for the purpose of structural classification. Splices or intersections of such runners shall be attached with through connectors such as pop rivets, screws, pins, plates with end tabs or other approved connectors.
  2. Corridors and lobbies. Expansion joints shall be provided in the ceiling at intersections of corridors and at junctions of corridors and lobbies or other similar areas.
  3. Lay-in panels. Metal panels and panels weighing more than ½ pounds per square foot (24 N/m2) other than acoustical tiles shall be positively attached to the ceiling suspension runners.
  4. Lateral force bracing. Lateral force bracing is required for all ceiling areas except that they shall be permitted to be omitted in rooms with floor areas up to 144 square feet when perimeter support in accordance with ASTM E 580 Sections 5.2.2 and 5.2.3 are provided and perimeter walls are designed to carry the ceiling lateral forces.

  5. Ceiling fixtures. Fixtures installed in acoustical tile or lay-in panel ceilings shall be mounted in a manner that will not compromise ceiling performance.

    All recessed or drop-in light fixtures and grilles shall be supported directly from the fixture housing to the structure above with a minimum of two 12-gage wires located at diagonally opposite corners. Leveling and positioning of fixtures may be provided by the ceiling grid. Fixture support wires may be slightly loose to allow the fixture support wires may be slightly loose to allow the fixture to seat in the grid system. Fixtures shall not be supported from main runners or cross runners if the weight of the fixtures causes the total dead load to exceed the deflection capability of the ceiling suspension system.

    Fixtures shall not be installed so that the main runners or cross runners will be eccentrically loaded.

    Surface-mounted fixtures shall be attached to the main runner with at least two positive clamping devices made of material with a minimum of 14 gage. Rotational spring catches do not comply. A 12-gage suspension wire shall be attached to each clamping device and to the structure above.

  6. Partitions. Where the suspended ceiling system is required to provide lateral support for the permanent or relocatable partitions, the connection of the partition to the ceiling system, the ceiling system members and their connections, and the lateral force bracing shall be designed to support the reaction force of the partition from prescribed loads applied perpendicular to the face of the partition. Partition connectors, the suspended ceiling system and the lateral-force bracing shall all be engineered to suit the individual partition application and shall be shown or defined in the drawings or specifications.

1615.10.14 ASCE 7, Section 13.6.5. Modify ASCE 7, Section 13.6.5 by deleting Item 6 in Section 13.6.5.5 and adding Section 13.6.5.6 as follows:

13.6.5.6 Conduit, cable tray, and other electrical distribution systems (raceways). Raceways shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Conduit greater than 2.5 inches (64 mm) trade size and attached to panels, cabinets or other equipment subject to seismic relative displacement, Dp, shall be provided with flexible connections or designed for seismic forces and seismic relative displacements as required in Section 13.3.

Exceptions:

  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for raceways where either:
    1. Trapeze assemblies are used to support raceways and the total weight of the raceway supported by trapeze assemblies is less than 10 lb/ft (146 N/m), or
    2. The raceway is supported by hangers and each hanger in the raceway run is 12 in. (305 mm) or less in length from the raceway support point to the supporting structure. Where rod hangers are used, they shall be equipped with swivels to prevent inelastic bending in the rod.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for conduit, regardless of the value of lp, where the conduit is less than 2.5 in. (64 mm) trade size.

1615.10.15 ASCE 7, Section 13.6.7. Replace ASCE 7, Section 13.6.7 by the following:

13.6.7 Ductwork. HVAC and other ductwork shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Ductwork designed to carry toxic, highly toxic or explosive gases,

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or used for smoke control shall be designed and braced without considering the exceptions noted below.

Exceptions:

  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for ductwork where either:
    1. Trapeze assemblies are used to support ductwork and the total weight of the ductwork supported by trapeze assemblies is less than 10 lb/ft (146 N/m); or
    2. The ductwork is supported by hangers and each hanger in the duct run is 12 in. (305 mm) or less in length from the duct support point to the supporting structure. Where rod hangers are used, they shall be equipped with swivels to prevent inelastic bending in the rod.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required where provisions are made to avoid impact with larger ducts or mechanical components or to protect the ducts in the event of such impact; and HVAC ducts have a cross-sectional area of 6 ft2 (0.557 m2) or less, or weigh 10 lb/ft (146 N/m) or less.

HVAC duct systems fabricated and installed in accordance with standards approved by the authority having jurisdiction shall be deemed to meet the lateral bracing requirements of this section.

Components that are installed in-line with the duct system and have an operating weight greater than 75 lb (334 N), such as fans, heat exchangers and humidifiers, shall be supported and laterally braced independent of the duct system, and such braces shall meet the force requirements of Section 13.3.1. Appurtenances such as dampers, louvers and diffusers shall be positively attached with mechanical fasteners. Unbraced piping attached to in-line equipment shall be provided with adequate flexibility to accommodate the seismic relative displacements.

1615.10.16 ASCE 7, Section 13.6.8. Replace ASCE 7, Section 13.6.8 by the following:

13.6.8 Piping systems. Unless otherwise noted in this section, piping systems shall be designed for the seismic forces and seismic relative displacements of Section 13.3. ASME pressure piping systems shall satisfy the requirements of Section 13.6.8.1. Fire protection sprinkler piping shall satisfy the requirements of Section 13.6.8.2. Elevator system piping shall satisfy the requirements of Section 13.6.10.

Where other applicable material standards or recognized design bases are not used, piping design including consideration of service loads shall be based on the following allowable stresses:

  1. For piping constructed with ductile materials (e.g., steel, aluminum or copper), 90 percent of the minimum specified yield strength.
  2. For threaded connections in piping constructed with ductile materials, 70 percent of the minimum specified yield strength.
  3. For piping constructed with nonductile materials (e.g., cast iron or ceramics), 10 percent of the material minimum specified tensile strength.
  4. For threaded connections in piping constructed with nonductile materials, 8 percent of the material minimum specified tensile strength.

Piping not detailed to accommodate the seismic relative displacements at connections to other components shall be provided with connections having sufficient flexibility to avoid failure of the connection between the components.

13.6.8.1 ASME Pressure piping systems. Pressure piping systems, including their supports, designed and constructed in accordance with ASME B 31 shall be deemed to meet the force, displacement and other requirements of this section. In lieu of specific force and displacement requirements provided in ASME B 31, the force and displacement requirements of Section 13.3 shall be used.

13.6.8.2 Fire protection sprinkler piping systems. Fire protection sprinkler piping designed and constructed in accordance with NFPA 13 shall be deemed to meet the force and displacement requirements of this section. The exceptions of Section 13.6.8.3 shall not apply.

Exception: Pipe hangers, bracing and anchor capacities shall be determined in accordance with material chapters of the California Building Code, in lieu of using those in NFPA 13. The force and displacement requirements of Section 13.3 or those in the NFPA 13 may be used for design.

13.6.8.3 Exceptions. Design of piping systems and attachments for the seismic forces and relative displacements of Section 13.3 shall not be required where one of the following conditions apply:

  1. Trapeze assemblies are used to support piping whereby no single pipe exceeds the limits set forth in 3a. or b. below and the total weight of the piping supported by the trapeze assemblies is less than 10 lb/ft (146 N/m).
  2. The piping is supported by hangers and each hanger in the pipingrun is 12 in. (305 mm) or less in length from the top of the pipe to the supporting structure. Where pipes are supported on a trapeze, the trapeze shall be supported by hangers having a length of 12 in. (305 mm) or less. Where rod hangers are used, they shall be equipped with swivels, eye nuts or other devices to prevent bending in the rod. 74
  3. Piping having an Rp in Table 13.6-1 of 4.5 or greater is used and provisions are made to avoid impact with other structural or nonstructural components or to protect the piping in the event of such impact and where the following size requirements are satisfied:
    1. For Seismic Design Categories D, E or F and values of Ip greater than one, the nominal pipe size shall be 1 inch (25 mm) or less.
    2. For Seismic Design Categories D, E or F where Ip = 1.0 the nominal pipe size shall be 3 inches (80 mm) or less.

The exceptions above shall not apply to elevator piping.

13.6.8.4 Other piping systems. Piping not designed and constructed in accordance with ASME B 31 or NFPA 13 shall comply with the requirements of Section 13.6.11.

1615.10.17 ASCE 7, Section 13.6.10.1. Modify ASCE 7 Section 13.6.10.1 by adding Section 13.6.10.1.1 as follows:

13.6.10.1.1 Elevators guide rail support. The design of guide rail support bracket fastenings and the supporting structural framing shall use the weight of the counterweight or maximum weight of the car plus not more than 40 percent of its rated load. The seismic forces shall be assumed to be distributed one-third to the top guiding members and two-thirds to the bottom guiding members of cars and counterweights, unless other substantiating data are provided. In addition to the requirements of ASCE 7 Section 13.6.10.1, the minimum seismic forces shall be 0.5g acting in any horizontal direction.

1615.10.18 ASCE 7, Section 13.6.10.4. Replace ASCE 7 Section 13.6.10.4 as follows:

13.6.10.4 Retainer plates. Retainer plates are required at the top and bottom of the car and counterweight, except where safety devices acceptable to the enforcement agency are provided which meet all requirements of the retainer plates, including full engagement of the machined portion of the rail. The design of the car, cab stabilizers, counterweight guide rails and counterweight frames for seismic forces shall be based on the following requirements:

  1. The seismic force shall be computed per the requirements of ASCE 7 Section 13.6.10.1. The minimum horizontal acceleration shall be 0.5g for all buildings.
  2. Wp shall equal the weight of the counterweight or the maximum weight of the car plus not less than 40 percent of its rated load.
  3. With the car or counterweight located in the most adverse position, the stress in the rail shall not exceed the limitations specified in these regulations, nor shall the deflection of the rail relative to its supports exceed the deflection listed below:
    RAIL SIZE (weight per foot of length, pounds)WIDTH OF MACHINED SURFACE (inches)ALLOWABLE RAIL DEFLECTION (inches)
    For SI: 1 inch = 25 mm, 1 foot = 305 mm, 1 pound = 0.454 kg.
    Note: Deflection limitations are given to maintain a consistent factor of safety against disengagement of retainer plates from the guide rails during an earthquake.
    8 1 ¼ 0.20
    11 1 ½ 0.30
    12 1 ¾ 0.40
    15 1 31/32 0.50
    18 ½ 1 31/32 0.50
    22 ½ 2 0.50
    30 2 ¼ 0.50
  4. Where guide rails are continuous over supports and rail joints are within 2 feet (610 mm) of their supporting brackets, a simple span may be assumed.
  5. The use of spreader brackets is allowed.
  6. Cab stabilizers and counterweight frames shall be designed to withstand computed lateral load with a minimum horizontal acceleration of 0.5g.

1615.10.19 ASCE 7, Section 16.1.3.2. Modify ASCE 7 Section 16.1.3.2 by the following:

Where next generation attenuation relations are used in accordance with CBC Section 1802A.6.2, each pair of motion shall be scaled such that for each period between 0.2T and 1.5T, the average of the SRSS spectra from all horizontal component pairs does not fall below the corresponding ordinate of the maximum considered earthquake (MCE) response spectrum determined using NGA relations.

At sites within 5 km of an active fault that controls the hazard, each pair of components shall be rotated to the fault-normal and fault-parallel direction of the causative fault, and shall be scaled so that average of the fault-normal components is not be less than the MCE response spectrum for each period between 0.2T and 1.5T.

1615.10.20 ASCE 7, Section 16.1.4. Modify ASCE 7 Section 16.1.4 by the following:

1615.10.21 ASCE 7, Section 16.2.4. Modify ASCE 7 Section 16.2.4 by the following:

  1. Where site is located within 3.1 miles (5 km) of and active fault at least seven ground motions shall be analyzed and response parameters shall be based on larger of the average of the maximum response with ground motions applied as follows:
    1. Each of the ground motions shall have their maximum component at the fundamental period aligned in one direction.
    2. Each of the ground motion's maximum component shall be rotated orthogonal to the previous analysis direction.
  2. Where site is located more than 3.1 miles (5 km) from an active fault at least 10 ground motions shall be analyzed. The ground motions shall be applied such that one-half shall have their maximum component aligned in one direction and the other half aligned in the orthogonal direction. The average of the maximum response of all the analyses shall be used for design.

1615.10.22 ASCE 7, Section 17.2.1. Modify ASCE 7 Section 17.2.1 by adding the following:

The importance factor, Ip, for parts and portions of a seismically isolated building shall be the same as that required for a fixed-base building of the same occupancy category.

1615.10.23 ASCE 7 Section 17.2.4.7. Modify ASCE 7 Section 17.2.4.7 by adding the following:

The effects of uplift and/or rocking shall be explicitly accounted for in the analysis and in the testing of the isolator units.

1615.10.24 ASCE 7, Section 17.2.5.2. Modify ASCE 7, Section 17.2.5.2 by adding the following:

The separation requirements for the building above the isolation system and adjacent buildings shall be the sum of the factored displacements for each building. The factors to be used in determining separations shall be:

  1. For seismically isolated buildings, the deformation resulting from the analyses using the maximum considered earthquake unmodified by RI.
  2. For fixed based buildings, Cd times the elastic deformations resulting from an equivalent static analysis using the seismic base shear computed via ASCE 7 Section 12.8.

1615.10.25 ASCE 7, Section 17.3.2. Modify ASCE 7, Section 17.3.2 by adding the following:

Where next generation attenuation relations are used in accordance with Section 1803A.6.2, each pair of motion shall be scaled such that for each period between 0.5TD and 1.25TM (Where TD and TM are defined in Section 17.5.3), the average of the SRSS spectra from all horizontal component pairs does not fall below the corresponding ordinate of the maximum considered earthquake (MCE) response spectrum determined using NGA relations.

At sites within 5 km of an active fault that controls the hazard, each pair of components shall be rotated to the fault-normal and fault-parallel direction of the causative fault, and shall be scaled so that average of the fault-normal components is not be less than the MCE response spectrum for each period between 0.5TD and 1.25TM.

1615.10.26 ASCE 7, Section 21.4. Replace ASCE 7, Section 21.4 by the following:

21.4 Design Acceleration Parameters. Where the site-specific procedure is used to determine the design ground motion in accordance with Section 21.3, the parameter SDS shall be taken as the spectral acceleration, Sa, obtained from the site-specific spectra at a period of 0.2 sec, except that it shall not be taken less than 90 percent of the peak spectral acceleration, Sa, at any period larger than 0.2 second. The parameter SDI shall be taken as the greater of the spectral acceleration, Sa, at a period of 1 sec or two times the spectral acceleration, Sa, at a period of 2 sec.

For use with the Equivalent Lateral Force Procedure, the site specific spectral acceleration, Sa at T shall be permitted to replace SDI/T in Equation 12.8-3 and SDITL/T2 in Equation 12.8-4. The parameter SDS calculated per this section shall be permitted to be used in Equations 12.8-2 and 12.8-5. The mapped value of SI shall be used in Equation 12.8-6. The parameters SMSand SMI shall be taken as 1.5 times SDS and SDI, respectively. The values so obtained shall not be less than 80 percent of the values determined in accordance with Section 11.4.3 for SMS and SMI and Section 11.4.4 for SDS and SDI.

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CALIFORNIA BUILDING CODE-MATRIX ADOPTION TABLE
CHAPTER 16A - STRUCTURAL DESIGN
Adopting agency BSC SFM HCD DSA OSHPD CSA DPH AGR DWR CEC CA SL SLC
1 2 1-AC AC SS SS/CC 1 2 3 4
Adopt entire chapter             X   X     X                
Adopt entire chapter as amended (amended sections listed below)                                        
Adopt only those sections that are listed below           X                            
Chapter/Section                                        
1607A.7.2           X                            
                                         
77 78

CHAPTER 16A
STRUCTURAL DESIGN

SECTION 1601 A
GENERAL

1601A.1 Scope. The provisions of this chapter shall govern the structural design of buildings, structures and portions thereof regulated by this code.

1601A.1.1 Application. The scope of application of Chapter 16A is as follows:

  1. Applications listed in Section 1.9.2.1, regulated by the Division of the State Architect-Structural Safety (DSA-SS). These applications include public elementary and secondary schools, community colleges and state-owned or state-leased essential services buildings.
  2. Applications listed in Sections 1.10.1 and 1.10.4, regulated by the Office of Statewide Health Planning and Development (OSHPD). These applications include hospitals, skilled nursing facilities, intermediate care facilities, and correctional treatment centers.

    Exception: [OSHPD 2] Single-story Type V skilled nursing or intermediate care facilities utilizing wood-frame or light-steel-frame construction as defined in Health and Safety Code Section 129725, which shall comply with Chapter 16 and any applicable amendments therein.

1601A.1.2 Amendments in this chapter. DSA-SS and OSHPD adopt this chapter and all amendments.

Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopting agency, as follows:

  1. Division of the State Architect-Structural Safety:

    [DSA-SS] - For applications listed in Section 1.9.2.1.

  2. Office of Statewide Health Planning and Development:

    [OSHPD 1] - For applications listed in Section 1.10.1.

    [OSHPD 4] - For applications listed in Section 1.10.4.

1601A.2 References. All referenced codes and standards listed in Chapter 35 shall include all the modifications contained in this code to referenced standards. In the event of any discrepancy between this code and a referenced standard, refer to Section 1.1.7.

1601A.3 Enforcement agency approval. In addition to the requirements of California Code of Regulations (C.C.R.) Title 24, Parts 1 and 2, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the design professional are also subject to approval by the enforcement agency.

SECTION 1602A
DEFINITIONS AND NOTATIONS

1602A.1 Definitions. The following words and terms shall, for the purposes of this chapter, have the meanings shown herein.

ALLOWABLE STRESS DESIGN. A method of proportioning structural members, such that elastically computed stresses produced in the members by nominal loads do not exceed specified allowable stresses (also called “ working stress design”).

ALTERNATIVE SYSTEM. [OSHPD 1 & 4] Alternative materials, design and methods of construction in accordance with Section 104.11, Section 11.1.4 of ASCE 7 or structural design criteria as approved by the enforcement agency.

DEAD LOADS. The weight of materials of construction incorporated into the building, including but not limited to walls, floors, roofs, ceilings, stairways, built-in partitions, finishes, cladding and other similarly incorporated architectural and structural items, and the weight of fixed service equipment, such as cranes, plumbing stacks and risers, electrical feeders, heating, ventilating and air-conditioning systems and automatic sprinkler systems.

DESIGN STRENGTH. The product of the nominal strength and a resistance factor (or strength reduction factor).

DIAPHRAGM. A horizontal or sloped system acting to transmit lateral forces to the vertical-resisting elements. When the term “diaphragm” is used, it shall include horizontal bracing systems.

Diaphragm, blocked. In light-frame construction, a diaphragm in which all sheathing edges not occurring on a framing member are supported on and fastened to blocking.

Diaphragm boundary. In light-frame construction, a location where shear is transferred into or out of the diaphragm sheathing. Transfer is either to a boundary element or to another force-resisting element.

Diaphragm chord. A diaphragm boundary element perpendicular to the applied load that is assumed to take axial stresses due to the diaphragm moment.

Diaphragm flexible. A diaphragm is flexible for the purpose of distribution of story shear and torsional moment where so indicated in Section 12.3.1 of ASCE 7, as modified in Section 1613A.6.1.

Diaphragm, rigid. A diaphragm is rigid for the purpose of distribution of story shear and torsional moment when the lateral deformation of the diaphragm is less than or equal to two times the average story drift.

DURATION OF LOAD. The period of continuous application of a given load, or the aggregate of periods of intermittent applications of the same load.

ENFORCEMENT AGENT. That individual within the agency or organization charged with responsibility for agency or organization compliance with the requirements of this code.

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Used interchangeably with “Building Official” and “Code Official”.

ESSENTIAL FACILITIES. Buildings and other structures that are intended to remain operational in the event of extreme environmental loading from flood, wind, snow or earthquakes.

FABRIC PARTITION. A partition consisting of a finished surface made of fabric, without a continuous rigid backing, that is directly attached to a framing system in which the vertical framing members are spaced greater than 4 feet (1219 mm) on center.

FACTORED LOAD. The product of a nominal load and a load factor.

GUARD. See Section 1002.1.

HOSPITAL BUILDING. Any building defined in Section 129725, Health and Safety Code.

IMPACT LOAD. The load resulting from moving machinery, elevators, craneways, vehicles and other similar forces and kinetic loads, pressure and possible surcharge from fixed or moving loads.

LIMIT STATE. A condition beyond which a structure or member becomes unfit for service and is judged to be no longer useful for its intended function (serviceability limit state) or to be unsafe (strength limit state).

LIVE LOADS. Those loads produced by the use and occupancy of the building or other structure and do not include construction or environmental loads such as wind load, snow load, rain load, earthquake load, flood load or dead load.

LIVE LOADS (ROOF). Those loads produced (1) during maintenance by workers, equipment and materials; and (2) during the life of the structure by movable objects such as planters and by people.

LOAD AND RESISTANCE FACTOR DESIGN (LRFD). A method of proportioning structural members and their connections using load and resistance factors such that no applicable limit state is reached when the structure is subjected to appropriate load combinations. The term “LRFD” is used in the design of steel and wood structures.

LOAD EFFECTS. Forces and deformations produced in structural members by the applied loads.

LOAD FACTOR. A factor that accounts for deviations of the actual load from the nominal load, for uncertainties in the analysis that transforms the load into a load effect, and for the probability that more than one extreme load will occur simultaneously.

LOADS. Forces or other actions that result from the weight of building materials, occupants and their possessions, environmental effects, differential movement and restrained dimensional changes. Permanent loads are those loads in which variations over time are rare or of small magnitude, such as dead loads. All other loads are variable loads (see also “Nominal loads”).

NOMINAL LOADS. The magnitudes of the loads specified in this chapter (dead, live, soil, wind, snow, rain, flood and earthquake).

OCCUPANCY CATEGORY. A category used to determine structural requirements based on occupancy.

OTHER STRUCTURES. Structures, other than buildings, for which loads are specified in this chapter.

PANEL (PART OF A STRUCTURE). The section of a floor, wall or roof comprised between the supporting frame of two adjacent rows of columns and girders or column bands of floor or roof construction.

RESISTANCE FACTOR. A factor that accounts for deviations of the actual strength from the nominal strength and the manner and consequences of failure (also called “strength reduction factor”).

STRENGTH, NOMINAL. The capacity of a structure or member to resist the effects of loads, as determined by computations using specified material strengths and dimensions and equations derived from accepted principles of structural mechanics or by field tests or laboratory tests of scaled models, allowing for modeling effects and differences between laboratory and field conditions.

STRENGTH, REQUIRED. Strength of a member, cross section or connection required to resist factored loads or related internal moments and forces in such combinations as stipulated by these provisions.

STRENGTH DESIGN. A method of proportioning structural members such that the computed forces produced in the members by factored loads do not exceed the member design strength [also called “load and resistance factor design”(LRFD)]. The term “strength design” is used in the design of concrete and masonry structural elements.

VEHICLE BARRIER SYSTEM. A system of building components near open sides of a garage floor or ramp or building walls that act as restraints for vehicles.

NOTATIONS.

D = Dead load.

E = Combined effect of horizontal and vertical earthquake induced forces as defined in Section 12.4.2 of ASCE 7.

F = Load due to fluids with well-defined pressures and maximum heights.

Fa = Flood load in accordance with Chapter 5 of ASCE 7.

H = Load due to lateral earth pressures, ground water pressure or pressure of bulk materials.

L = Live load, except roof live load, including any permitted live load reduction.

Lr = Roof live load including any permitted live load reduction.

R = Rain load.

S = Snow load.

T = Self-straining force arising from contraction or expansion resulting from temperature change, shrinkage, moisture change, creep in component materials, movement due to differential settlement or combinations thereof.

W = Load due to wind pressure.

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SECTION 1603A
CONSTRUCTION DOCUMENTS

1603A.1 General. Construction documents shall show the size, section and relative locations of structural members with floor levels, column centers and offsets dimensioned. The design loads and other information pertinent to the structural design required by Sections 1603A.1.1 through 1603A.1.9 shall be indicated on the construction documents.

Exception: Construction documents for buildings constructed in accordance with the conventional light-frame construction provisions of Section 2308 shall indicate the following structural design information:

  1. Floor and roof live loads.
  2. Ground snow load, Pg.
  3. Basic wind speed (3-second gust), miles per hour (mph) (km/hr) and wind exposure.
  4. Seismic design Category and site class.
  5. Flood design data, if located in flood hazard areas established in Section 1612A.3.
  6. Design load-bearing values of soils.

[DSA-ASS] Additional requirements are included in Section 4-210 and 4-317 of the California Administrative Code (Part 1, Title 24, C.C.R).

[OSHPD 1] Additional requirements are included in Section 7-115 and 7-125 of the California Administrative Code (Part 1, Title 24, C.C.R).

1603A.1.1 Floor live load. The uniformly distributed, concentrated and impact floor live load used in the design shall be indicated for floor areas. Use of live load reduction in accordance with Section 1607A.9 shall be indicated for each type of live load used in the design.

1603A.1.2 Roof live load. The roof live load used in the design shall be indicated for roof areas (Section 1607A.11).

1603A.1.3 Roof snow load. The ground snow load, Pg, shall be indicated. In areas where the ground snow load, Pg, exceeds 10 pounds per square foot (psf) (0.479 kN/m2), the following additional information shall also be provided, regardless of whether snow loads govern the design of the roof:

  1. Flat-roof snow load, Pf.
  2. Snow exposure factor, Ce.
  3. Snow load importance factor, I.
  4. Thermal factor, Ct.

1603A.1.4 Wind design data. The following information related to wind loads shall be shown, regardless of whether wind loads govern the design of the lateral-force-resisting system of the building:

  1. Basic wind speed (3-second gust), miles per hour (km/hr).
  2. Wind importance factor, I, and occupancy category.
  3. Wind exposure. Where more than one wind exposure is utilized, the wind exposure and applicable wind direction shall be indicated.
  4. The applicable internal pressure coefficient.
  5. Components and cladding. The design wind pressures in terms of psf (kN/m2) to be used for the design of exterior component and cladding materials not specifically designed by the registered design professional.

1603A.1.5 Earthquake design data. The following information related to seismic loads shall be shown, regardless of whether seismic loads govern of the design of the lateral-force-resisting system of the building:

  1. Seismic importance factor, I, and occupancy category.
  2. Mapped spectral response accelerations, Ss and S1.
  3. Site class.
  4. Spectral response coefficients, SDS and SDI.
  5. Seismic design category.
  6. Basic seismic-force-resisting system(s).
  7. Design base shear.
  8. Seismic response coefficient(s), Cs.
  9. Response modification factor(s), R.
  10. Analysis procedure used.
  11. Applicable horizontal structural irregularities.
  12. Applicable vertical structural irregularities.

1603A.1.5.1 Connections. Connections that resist design seismic forces shall be designed and detailed on the design drawings.

1603A.1.6 Geotechnical information. The design load-bearing values of soils shall be shown on the construction documents.

1603A.1.7 Flood design data. For buildings located in whole or in part in flood hazard areas as established in Section 1612A.3, the documentation pertaining to design, if required in Section 1612A.5, shall be included and the following information, referenced to the datum on the community's Flood Insurance Rate Map (FIRM), shall be shown, regardless of whether flood loads govern the design of the building:

  1. In flood hazard areas not subject to high-velocity wave action, the elevation of the proposed lowest floor, including the basement.
  2. In flood hazard areas not subject to high-velocity wave action, the elevation to which any nonresidential building will be dry floodproofed.
  3. In flood hazard areas subject to high-velocity wave action, the proposed elevation of the bottom of the lowest horizontal structural member of the lowest floor, including the basement.

1603A.1.8 Special loads. Special loads that are applicable to the design of the building, structure or portions, thereof shall be indicated along with the specified section of this code that addresses the special loading condition.

1603A.1.9 Systems and components requiring special inspections for seismic resistance. Construction documents

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or specifications shall be prepared for those systems and components requiring special inspection for seismic resistance as specified in Section 1707.1 by the registered design professional responsible for their design and shall be submitted for approval in accordance with Section 107.1 Reference to seismic standards in lieu of detailed drawings is acceptable.

1603A.1.10 Construction procedures. Where unusual erection or construction procedures are considered essential by the project structural engineer or architect in order to accomplish the intent of the design or influence the design, such procedure shall be indicated on the construction documents.

SECTION 1604A
GENERAL DESIGN REQUIREMENTS

1604A.1 General. Building, structures and parts thereof shall be designed and constructed in accordance with strength design, load and resistance factor design, allowable stress design, empirical design or conventional construction methods, as permitted by the applicable material chapters.

1604A.2 Strength. Buildings and other structures, and parts thereof, shall be designed and constructed to support safely the factored loads in load combinations defined in this code without exceeding the appropriate strength limit states for the materials of construction. Alternatively, buildings and other structures, and parts thereof, shall be designed and constructed to support safely the nominal loads in load combinations defined in this code without exceeding the appropriate specified allowable stresses for the materials of construction.

Loads and forces occupancies or uses not covered in this chapter shall be subject to the approval of the building official.

1604A.3 Serviceability. Structural systems and members thereof shall be designed to have adequate stiffness to limit deflections and lateral drift. See Section 12.12.1 of ASCE 7 for drift limits applicable to earthquake loading.

1604A.3.1 Deflections. The deflections of structural members shall not exceed the more restrictive of the limitations of Sections 1604A.3.2 through 1604A.3.6 or that permitted by Table 1604A.3.

1604A.3.2 Reinforced concrete. The deflection of reinforced concrete structural members shall not exceed that permitted by ACI 318.

1604A.3.3 Steel. The deflection of steel structural members shall not exceed that permitted by AISC 360, AISI S100, ASCE 3, ASCE 8, SJI CJ-1.0, SJI JG-1.1, SJI K-1.1 or SJI LH/DLH-1.1, as applicable.

1604A.3.4 Masonry. The deflection of masonry structural members shall not exceed that permitted by TMS 402/ACI 530/ASCE 5.

1604A.3.5 Aluminum. The deflection of aluminum structural members shall not exceed that permitted by AA ADM1.

1604A.3.6 Limits. Deflection of structural members over span, l, shall not exceed that permitted by Table 1604A.3.

1604A.3.7 Horizontal diaphragms. The maximum span-width ratio for any roof or floor diaphragm shall not exceed those given in Table 4.2.4 of AF & PA SDPWS or ICC-ES AC 43 unless test data and design calculations acceptable to the enforcement agency are submitted and approval for the use of other span-width ratios. Concrete diaphragm shall not exceed span-width ratios for equivalent composite floor diaphragm in ICC-ES AC 43.

1604A.3.8 Deflections. Deflection criteria for materials not specified shall be developed by the project architect or structural engineer in a manner consistent with the provisions of this section and approved by the enforcement agency.

TABLE 1604.3
DEFLECTION LIMITSa,b,c,h,i
CONSTRUCTIONLS or WfD+ Ld,g
For SI: 1 foot = 304.8 mm.
a. For structural roofing and siding made of formed metal sheets, the total load deflection shall not exceed l/60. For secondary roof structural members supporting formed metal roofing, the live load deflection shall not exceed 11150. For secondary wall members supporting formed metal siding, the design wind load deflection shall not exceed l/90. For roofs, this exception only applies when the metal sheets have no roof covering.
b. Interior partitions not exceeding 6 feet in height and flexible, folding and portable partitions are not governed by the provisions of this section. The deflection criterion for interior partitions is based on the horizontal load defined in Section 1607A.13.
c. See Section 2403 for glass supports.
d. For wood structural members having a moisture content of less than 16 percent at time of installation and used under dry conditions, the deflection resulting from L + 0.5D is permitted to be substituted for the deflection resulting from L + D.
e. The above deflections do not ensure against ponding. Roofs that do not have sufficient slope or camber to assure adequate drainage shall be investigated for ponding. See Section 1611 A for rain and ponding requirements and Section 1503.4 for roof drainage requirements.
f. The wind load is permitted to be taken as 0.7 times the “component and cladding” loads for the purpose of determining deflection limits herein.
g. For steel structural members, the dead load shall be taken as zero.
h. For aluminum structural members or aluminum panels used in skylights and sloped glazing framing, roofs or walls of sunroom additions or patio covers, not supporting edge of glass or aluminum sandwich panels, the total load deflection shall not exceed l/60. For continuous aluminum structural members supporting edge of glass, or aluminum sandwich panels, the total load deflection shall not exceed l/175 for each glass lite or l/60 for the entire length of the member, whichever is more stringent. For aluminum sandwich panels used in roofs or walls of sunroom additions or patio covers, the total load deflection shall not exceed l/120.
i. For Cantilever members, l shall be taken as twice the length of the cantilever.
Roof members:e   
Supporting plaster ceilingl/360l/360l/240
Supporting nonplaster ceilingl/240l/240l/180
Not supporting ceilingl/180l/180l/120
Floor membersl/360—l/240
Exterior walls and interior partitions:   
With brittle finishes—l/240—
With flexible finishes—l/120—
Veneered walls, anchored veneers and adhered veneers over 1 inch (25 mm) thick, including the mortar backing Section 1405.10 
Farm buildings——l/180
Greenhouses——l/120
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1604A.4 Analysis. Load effects on structural members and their connections shall be determined by methods of structural analysis that into account equilibrium, general stability, geometric compatibility and both short- and long-term material properties.

Members that tend to accumulate residual deformations under repeated service loads shall have included in their analysis the added eccentricities expected to occur during their service life.

Any system or method of construction to be used shall be based on a rational analysis in accordance with well-established principles of mechanics. Such analysis shall result in a system that provides a complete load path capable of transferring loads from their point of origin to the load-resisting elements.

The total lateral force shall be distributed to the various vertical elements of the lateral-force-resisting system in proportion to their rigidities, considering the rigidity of the horizontal bracing system or diaphragm. Rigid elements assumed not to be a part of the lateral-force-resisting system are permitted to be incorporated into buildings provided their effect on the action of the system is considered and provided for in the design. Except where diaphragms are flexible, or are permitted to be analyzed as flexible, provisions shall be made for the increased forces induced on resisting elements of the structural system resulting from torsion due to eccentricity between the center of application of the lateral forces and the center of rigidity of the lateral-force-resisting system.

Every structure shall be designed to resist the overturning effects caused by the lateral forces specified in this chapter. See Section 1609A for wind loads, Section 1610A for lateral soil loads and Section 1613A for earthquake loads.

1604A.5 Occupancy category. Each building and structure shall be assigned an occupancy category in accordance with Table 1604A.5.

1604A.5.1 Multiple occupancies. Where a building or structure is occupied by two or more occupancies not included in the same occupancy category, it shall be assigned the classification of the highest occupancy category corresponding to the various occupancies. Where buildings or structures have two or more portions that are structurally separated, each portion shall be separately classified. Where a separated portion of a building or structure provides required access to, required egress from or shares life safety components with another portion having a higher occupancy category, both portions shall be assigned to the higher occupancy category.

1604A.6 In-situ load tests. The building official is authorized to require an engineering analysis or a load test, or both, of any construction whenever there is reason to question the safety of the construction for the intended occupancy. Engineering analysis and load tests shall be conducted in accordance with Section 1714.

1604A.7 Preconstruction load tests. Materials and methods of construction that are not capable of being designed by approved engineering analysis or that do not comply with the applicable material design standards listed in Chapter 35, or alternative test procedures in accordance with Section 1712A, shall be load tested in accordance with Section 1715A.

1604A.8 Anchorage.

1604A.8.1 General. Anchorage of the roof to walls and columns, and of walls and columns to foundations, shall be provided to resist the uplift and sliding forces that result from the application of the prescribed loads.

1604A.8.2 Walls. Walls shall be anchored to floors, roofs and other structural elements that provide lateral support for the wall. Such anchorage shall provide a positive direct connection capable of resisting the horizontal forces specified in this chapter but not less than the minimum strength design horizontal force specified in Section 11.7.3 of ASCE 7, substituted for “E” in the load combinations of Section 1605A.2 or 1605A.3. Concrete and masonry walls shall be designed to resist bending between anchors where the anchor spacing exceeds 4 feet (1219 mm). Required anchors in masonry walls of hollow units or cavity walls shall be embedded in a reinforced grouted structural element of the wall. See Sections 1609A for wind design requirements and 1613A for earthquake design requirements.

1604A.8.3 Decks. Where supported by attachment to an exterior wall, decks shall be positively anchored to the primary structure and designed for both vertical and lateral loads as applicable. Such attachment shall not be accomplished by the use of toenails or nails subject to withdrawal. Where positive connection to the primary building structure cannot be verified during inspection, decks shall be self-supporting. Connections of decks with cantilevered framing members to exterior walls or other framing members shall be designed for both of the following:

  1. The reactions resulting from the dead load and live load specified in Table 1607A.1, or the snow load specified in Section 1608A, in accordance with Section 1605A, acting on all portions of the deck.
  2. The reactions resulting from the dead load and live load specified in Table 1607A.1, or the snow load specified in Section 1608A, acting on the cantilevered portion of the deck, and no live load or snow load on the remaining portion of the deck.

1604A.9 Counteracting structural actions. Structural members, systems, components and cladding shall be designed to resist forces due to earthquake and wind, with consideration of overturning, sliding and uplift. Continuous load paths shall be provided for transmitting these forces to the foundation. Where sliding is used to isolate the elements, the effects of friction between sliding elements shall be included as a force.

1604A.10 Wind and seismic detailing. Lateral-force-resisting systems shall meet seismic detailing requirements and limitations prescribed in this code and ASCE 7, excluding Chapter 14 and Appendix 11A, even when wind load effects are greater than seismic load effects.

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TABLE 1604A.5
OCCUPANCY CATEGORY OF BUILDINGS AND OTHER STRUCTURES
OCCUPANCY CATEGORYNATURE OF OCCUPANCY
a. For purposes of occupant load calculation, occupancies required by Table 1004.1.1 to use gross floor area calculations shall be permitted to use net floor areas to determine the total occupant load.
IBuildings and other structures that represent a low hazard to human life in the event of failure, including but not limited to:
  • Agricultural facilities.
  • Certain temporary facilities.
  • Minor storage facilities.
IIBuildings and other structures except those listed in Occupancy Categories I, III and IV
IIIBuildings and other structures that represent a substantial hazard to human life in the event of failure, including but not limited to:
  • Buildings and other structures whose primary occupancy is public assembly with an occupant load greater than 300.
  • Buildings and other structures containing elementary school, secondary school or day care facilities with an occupant load greater than 250.
  • Buildings and other structures containing adult education facilities, such as colleges and universities, with an occupant load greater than 500.
  • Group I-3 occupancies.
  • Any other occupancy with an occupant load greater than 5,000a.
  • Power-generating stations, water treatment facilities for potable water, waste water treatment facilities and other public utility facilities not included in Occupancy Category IV.
  • Buildings and other structures not included in Occupancy Category IV containing sufficient quantities of toxic or explosive substances to be dangerous to the public if released.
IVBuildings and other structures designated as essential facilities, including but not limited to:
  • [OSHPD 1 & 4] Hospital Buildings as defined in CCR. Title 24, Part 1, Section 7-111 and all structures required for their continuous operation or access/egress.
  • Fire, rescue, ambulance and police stations and emergency vehicle garages.
  • Designated earthquake, hurricane or other emergency shelters.
  • Designated emergency preparedness, communications and operations centers and other facilities required for emergency response [DSA-SS] as defined in C CR. Title 24, Part 1, Section 4-207 and all structures required/or their continuous operation or access/egress.
  • Power-generating stations and other public utility facilities required as emergency backup facilities for Occupancy Category IV structures.
  • Structures containing highly toxic materials as defined by Section 307 where the quantity of the material exceeds the maximum allowable quantities of Table 307.1(2).
  • Aviation control towers, air traffic control centers and emergency aircraft hangars.
  • Buildings and other structures having critical national defense functions.
  • Water storage facilities and pump structures required to maintain water pressure for fire suppression.

SECTION 1605A
LOAD COMBINATIONS

1605A.1 General. Buildings and other structures and portions thereof shall be designed to resist:

  1. The load combinations specified in Section 1605A.2, 1605A.3.1 or 1605A.3.2,
  2. The load combinations specified in Chapters 18 through 23, and
  3. The load combinations with overstrength factor specified in Section 12.4.3.2 of ASCE 7 where required by Section 12.2.5.2, 12.3.3.3 or 12.10.2.1 of ASCE 7. With the simplified procedure of ASCE 7 Section 12.14, the load combinations with overstrength factor of Section 12.14.3.2 of ASCE 7 shall be used.

Applicable loads shall be considered, including both earthquake and wind, in accordance with the specified load combinations. Each load combination shall also be investigated with one or more of the variable loads set to zero.

Where the load combinations with overstrength factor in Section 12.4.3.2 of ASCE 7 apply, they shall be used as follows:

  1. The basic combinations for strength design with overstrength factor in lieu of Equations 16A-5 and 16A-7 in Section 1605A.2.1.
  2. The basic combinations for allowable stress design with overstrength factor in lieu of Equations 16A-12, 16A-13 and 16A-15 in Section 1605A.3.1.
  3. The basic combinations for allowable stress design with overstrength factor in lieu of Equations 16A-20 and 16A-21 in Section 1605A.3.2.

1605A.1.1 Stability. Regard less of which load combinations are used to design for strength, where overall structure

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stability (such as stability against overturning, sliding, or buoyancy) is being verified, use of the load combinations specified in Section 1605A.2 or 1605A.3 shall be permitted. Where the load combinations specified in Section 1605A.2 are used, strength reduction factors applicable to soil resistance shall be provided by a registered design professional. The stability of retaining walls shall be verified in accordancewith Section 1807A.2.3. When using allowable stress design, factor of safety for soil bearing values shall not be less than the overstrength factor of the structures supported.

1605A.2 Load combinations using strength design or load and resistance factor design.

1605A.2.1 Basic load combinations. Where strength design or load and resistance factor design is used, structures and portions thereof shall resist the most critical effects from the following combinations of factored loads:

Image

where:

f1 = 1 for floors in places of public assembly, for live loads in excess of 100 pounds per square foot (4.79 kN/m2), and for parking garage live load, and

= 0.5 for other live loads.

f2 = 0.7 for roof configurations (such as saw tooth) that do not shed snow off the structure, and

= 0.2 for other roof configurations.

Exception: Where other factored load combinations are specifically required by the provisions of this code, such combinations shall take precedence.

1605A.2.2 Flood loads. Where flood loads, Fa, are to be considered in the design, the load combinations of Section 2.3.3 of ASCE 7 shall be used.

1605A.3 Load combinations using allowable stress design.

1605A.3.1 Basic load combinations. Where allowable stress design (working stress design), as permitted by this code, is used, structures and portions thereof shall resist the most critical effects resulting from the following combinations of loads:

Image

Image

Exceptions:

  1. Crane book loads need not be combined with roof live load or with more than three-fourths of the snow load or one-half of the wind load.
  2. Flat roof snow loads of 30 psf (1.44 kN/m2) or less and roof live loads of 30 psf or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.

1605A.3.1.1 Stress increases. Increases in allowable stresses specified in the appropriate material chapter or the referenced standards shall not be used with the load combinations of Section 1605A.3.1, except that increases shall be permitted in accordance with Chapter 23.

1605A.3.1.2 Flood loads. Where flood loads, Fa, are to be considered in design, the load combinations of Section 2.4.2 of ASCE 7 shall be used.

1605A.3.2 Alternative basic load combinations. In lieu of the basic load combinations specified in Section 1605A.3.1, structures and portions thereof shall be permitted to be designed for the most critical effects resulting from the following combinations. When using these alternative basic load combinations that include wind or seismic loads, allowable stresses are permitted to be increased or load combinations reduced where permitted by the material chapter of this code or the referenced standards. For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely to be in place during a design wind event shall be used. Where wind loads are calculated in accordance with Chapter 6 of ASCE 7, the coefficient ω in the following equations shall be taken as 1.3. For other wind loads, ω shall be taken as 1. When using these alternative load combinations to evaluate sliding, overturning and soil bearing at the soil-structure interface, the reduction of foundation overturning from Section 12.13.4 in ASCE 7 shall not be used. When using these alternative basic load combinations for proportioning foundations for loadings, which include seismic loads, the vertical seismic load effect, Eν, in Equation 12.4-4 of ASCE 7 is permitted to be taken equal to zero.

Image

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Exceptions:

  1. Crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind load.
  2. Flat roof snow loads of 30 psf (1.44 kN/m2) or less and roof live loads of 30 psf or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 psf (1.44 kN/m2), 20 percent shall be combined with seismic loads.

1605A.3.2.1 Other loads. Where F, H or T are to be considered in the design, each applicable load shall be added to the combinations specified in Section 1605A.3.2.

1605A.4 Heliports and helistops. Heliport and helistop landing areas shall be designed for the following loads, combined in accordance with Section 1605A:

  1. Dead load, D, plus the gross weight of the helicopter, Dh, plus snow load, S.
  2. Dead load, D, plus two single concentrated impact loads, L, approximately 8 feet (2438 mm) apart applied anywhere on the touchdown pad (representing each of the helicopter's two main landing gear, whether skid type or wheeled type), having a magnitude of 0.75 times the gross weight of the helicopter. Both loads acting together total 1.5 times the gross weight of the helicopter.
  3. Dead load, D, plus a uniform live load, L, of 100 psf (4.79 kN/m2).

SECTION 1606A
DEAD LOADS

1606A.1 Gerneral. Dead loads are those loads defined in Section 1602A.1. Dead loads shall be considered permanent loads.

1606A.2 Design dead load. For purposes of design, the actual weights of materials of construction and fixed service equipment shall be used. In the absence of definite information, values used shall be subject to the approval of the building official.

1606A.3 Roof dead loads. The design dead load shall provide for the weight of at least one additional roof covering in addition to other applicable loadings if the new roof covering is permitted to be applied over the original roofing without its removal, in accordance with Section 1510.

SECTION 1607A
LIVE LOADS

1607A.1 General. Live loads are those loads defined in Section 1602A.1.

1607A.2 Loads not specified. For occupancies or uses not designated in Table 1607A.1, the live load shall be determined in accordance with a method approved by the building official.

1607A.3 Uniform live loads. The live loads used in the design of buildings and other structures shall be the maximum loads expected by the intended use or occupancy but shall in no case be less than the minimum uniformly distributed unit loads required by Table 1607A.1.

TABLE 1607A.1
UNIFORMLY DISTRIBUTED LIVE LOADS, Lo, AND MINIMUM CONCENTRATED LIVE LOADSg
OCCUPANCY OR USEUNIFORM (psf)CONCENTRATED (lbs.)
1. Apartments (see residential)——
2. Access floor systems  
Office use502,000
Computer use1002,000
3. Armories and drill rooms150—
4. Assembly areas and theatersn,p —
Fixed seats (fastened to floor)60
Follow spot, projections and control rooms50
Lobbies100
Movable seats100
Stages and platforms125
Other assembly areas100
5. Balconies (exterior) and deckshSame as occupancy served—
6. Bowling alleys75—
7. Catwalks40300
8. Cornices60—
9. Corridors, except as otherwise indicated100—
10. Dance halls and ballrooms100—
11. Dining rooms and restaurants100—
12. Dwellings (see residential)——
13. Elevator machine room grating (on area of 4 in2)—300
14. Finish light floor plate construction (on area of 1 in 2)—200
15. Fire escapes
On single-family dwellings only		100
40		—
16. Garages (passenger vehicles only)40Note a
Trucks and busesSee Section 1607A.6
17. Grandstands (see stadium and arena bleachers)——
18. Gymnasiums,p main floors and balconies100—
19. Garages (passenger vehicles only)
Trucks and buses		See Section 1607A.7
20. Hospitals  
Corridors above first floor1001,000
Operating rooms, laboratories601,000
Patient rooms401,000
Mechanical and electrical equipment areas including open areas around equipment50 
Storage  
Light125 
Heavy250 
Dining Area (not used for assembly)1001,000
Kitchen and serving areas501,00086
21. Hotels (see residential)——
22. Librariesm  
Corridors above first floor801,000
Reading rooms601,000
Stack rooms150b1,000
23. Manufacturing  
Heavy2503,000
Light1252,000
24. Marquees75—
25. Office buildingsm  
Corridors above first floor802,000
File and computer rooms shall be designed for heavier loads based on anticipated occupancy——
Lobbies and first-floor corridors1002,000
Offices502,000
26. Penal institutions  
Cell blocks40—
Corridors100
27. Residential —
One- and two-family dwellings 
Uninhabitable attics without storagei10
Uninhabitable attics with limited storagei,j,k20
Habitable attics and sleeping areas30
All other areas40
Hotels and multifamily dwellings 
Private rooms and corridors serving them40
Public rooms and corridors serving them100
28. Reviewing stands, grandstands and bleacherspNote c
29. Roofs  
All roof surfaces subject to maintenance workers 300
Awnings and canopies  
Fabric construction supported by a lightweight rigid skeleton structure5
nonreducible
All other construction20 
Ordinary flat, pitched, and curved roofs20 
Primary roof members, exposed to a work floor  
Single panel point of lower chord of roof trusses or any point along primary structural members supporting roofs:  
Over manufacturing, storage warehouses, and repair garages 2,000
All other occupancies 300
Roofs used for other special purposesNote 1Note 1
Roofs used for promenade purposes60 
Roofs used for roof gardens or assembly purposes100 
30. Schoolsm  
Classrooms40o1,000
Corridors above first floor801,000
First-floor corridors1001,000
31. Scuttles, skylight ribs and accessible ceilings—200
32. Sidewalks, vehicular driveways and yards, subject to trucking250d8,000e
33. Skating rinks100—
34. Stadiums and arenas  
Bleachersp100c—
Fixed seats (fastened to floor)60c
35. Stairs and exits Note f
One- and two-family dwellings40 
All other100 
36. Storage warehouses  
(shall be designed for heavier loads if required for anticipated storage)  
Heavy250 
Light125 
37. Stores  
Retail  
First floor1001,000
Upper floors751,000
Wholesale, all floors1251,000
38. Vehicle barrier systemsSee Section
39. Walkways and elevated platforms (other than exitways)60—
40. Yards and terraces, pedestriansq100—
41. Storage racks and wall-hung cabinets.Total loadsm—
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2,
1 square foot = 0.0929 m2,
1 pound per square foot = 0.0479 kN/m2, 1 pound = 0.004448 kN,
1 pound per cubic foot = 16 kg/m3
a. Floors in garages or portions of buildings used for the storage of motor vehicles shall be designed for the uniformly distributed live loads of Table 1607A. 1 or the following concentrated loads: (1) for garages restricted to passenger vehicles accommodating not more than nine passengers, 3,000 pounds acting on an area of 4.5 inches by 4.5 inches; (2) for mechanical parking structures without slab or deck which are used for storing passenger vehicles only, 2,250 pounds per wheel.
b. The loading applies to stack room floors that support nonmobile, double-faced library bookstacks, subject to the following limitations:
1. The nominal bookstack unit height shall not exceed 90 inches;
2. The nominal shelf depth shall not exceed 12 inches for each face; and
3. Parallel rows of double-faced bookstacks shall be separated by aisles not less than 36 inches wide.
c. Design in accordance with ICC 300.
d. Other uniform loads in accordance with an approved method which contains provisions for truck loadings shall also be considered where appropriate.
e. The concentrated wheel load shall be applied on an area of 4.5 inches by 4.5 inches.
f. Minimum concentrated load on stair treads (on area of 4 square inches) is 300 pounds.
g. Where snow loads occur that are in excess of the design conditions, the structure shall be designed to support the loads due to the increased loads caused by drift buildup or a greater snow design determined by the building official (see Section 1608A). For special-purpose roofs, see section 1607A.11.2.2.
h. See Section 1604A.8.3 for decks attached to exterior walls.
i. Attics without storage are those where the maximum clear height between the joist and rafter is less than 42 inches, or where there are not two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide, or greater, located within the plane of the truss. For attics without storage, this live load need not be assumed to act concurrently with any other live load requirements.
j. For attics with limited storage and constructed with trusses, this live load need only be applied to those portions of the bottom chord where there are two or more adjacent trusses with the same web configuration capable of containing a rectangle 42 inches high by 2 feet wide or greater, located within the plane of the truss. The rectangle shall fit between the top of the bottom chord and the bottom of any other truss member, provided that each of the following criteria is met: 87
 
i. The attic area is accessible by a pull-down stairway or framed opening in accordance with Section 1209.2, and
ii. The truss shall have a bottom chord pitch less than 2:12.
iii. Bottom chords of trusses shall be designed for the greater of actual imposed dead load or 10 psf, uniformly distributed over the entire span.
k. Attic spaces served by a fixed stair shall be designed to support the minimum live load specified for habitable attics and sleeping rooms.
l. Roofs used for other special purposes shall be designed for appropriate loads as approved by the building official.
m. The minimum vertical design live load shall be as follows:
Paper media:
 12-inch-deep shelf33 pounds per lineal foot
 15-inch-deep shelf41 pounds per lineal foot, or
33 pounds per cubic foot per total volume of the rack or cabinet, whichever is less.
Film media:
 18-inch-deep shelf100 pounds per lineal foot, or
50 pounds per cubic foot per total volume of the rack or cabinet, whichever is less.
Other media:
20 pounds per cubic foot or 20 pounds per square foot, whichever is less, but not less than actual loads.
n. [DSA-SS] The following minimum loads for stage accessories apply:
1. Gridirons and fly galleries: 75 pounds per square foot uniform live load.
2. Loft block wells: 250 pounds per lineal foot vertical load and lateral load.
3. Head block wells and sheave beams: 250 pounds per lineal foot vertical load and lateral load. Head block wells and sheave beams shall be designed for all tributary loft block well loads. Sheave blocks shall be designed with a safety factor of five.
4. Scenery beams where there is no gridiron: 300 pounds per lineal foot vertical load and lateral load.
5. Ceiling framing over stages shall be designed for a uniform live load of 20 pounds per square foot. For members supporting a tributary area of 200 square feet or more, this additional load may be reduced to 15 pounds per square foot.
o. [DSA-SS] The minimum uniform live load for classroom occupancies is 50 psf.
p. [DSA-SS] The minimum uniform live load for a press box floor or accessible roof with railing is 100 psf.
q. [DSA-SS] Item 40 applies to pedestrian bridges and walkways that are not subjected to uncontrolled vehicle access.

1607A.4 Concentrated loads. Floors and other similar surfaces shall be designed to support the uniformly distributed live loads prescribed in Section 1607A.3 or the concentrated load, in pounds (kilonewtons), given in Table 1607A.1, whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall be assumed to be uniformly distributed over an area 2½ feet by 2½ feet [6¼ square feet (0.58 m2)] and shall be located so as to produce the maximum load effects in the structural members.

1607A.5 Partition loads. In office buildings and in other buildings where partition locations are subject to change, provisions for partition weight shall be made, whether or not partitions are shown on the construction documents, unless the specified live load exceeds 80 psf (3.83 kN/m2). The partition load shall not be less than a uniformly distributed live load of 15 psf (0.74 kN/m2).

1607A.6 Truck and bus garages. Minimum live loads for garages having trucks or buses shall be as specified in Table 1607A.6, but shall not be less than 50 psf (2.40 kN/m2), unless other loads are specifically justified and approved by the building official. Actual loads shall be used where they are greater than the loads specified in the table.

1607A.6.1 Truck and bus garage live load application. The concentrated load and uniform load shall be uniformly distributed over a 10-foot (3048 mm) width on a line normal to the centerline of the lane placed within a 12-foot-wide (3658 mm) lane. The loads shall be placed within their individual lanes so as to produce the maximum stress in each structural member. Single spans shall be designed for the uniform load in Table 1607A.6 and one simultaneous concentrated load positioned to produce the maximum effect. Multiple spans shall be designed for the uniform load in Table 1607A.6 on the spans and two simultaneous concentrated loads in two spans positioned to produce the maximum negative moment effect. Multiple span design loads, for other effects, shall be the same as for single spans.

TABLE 1607.6A.6
UNIFORM AND CONCENTRATED LOADS
LOADING CLASSaUNIFORM LOAD (pounds/linear foot of lane)CONCENTRATED LOAD(pounds)b
For moment designFor shear design
For SI: 1 pound per linear foot = 0.01459 kN/m, 1 pound=0.004448kN, 1 ton = 8.90 kN.
a. An H loading class designates a two-axle truck with a semitrailer. An HS loading class designates a tractor truck with a semitrailer. The numbers following the letter classification indicate the gross weight in tons of the standard truck and the year the loadings were instituted.
b. Section 1607.6.1 for the loading of multiple spans.
H20-44 and HS20-4464018,00026,000
H15-44 and HS15-4448013,50019,500

1607A.7 Loads on handrails, guards, grab bars, shower seats, dressing room bench seats and vehicle barrier systems. Handrails, guards, grab bars, accessible seats, accessible benches and vehicle barrier systems shall be designed and constructed to the structural loading conditions set forth in this section.

1607A.7.1 Handrails and guards. Handrails and guards shall be designed to resist a load of 50 pounds per linear foot (plf) (0.73 kN/m) applied in any direction at the top and to transfer this load through the supports to the structure. Glass handrail assemblies and guards shall also comply with Section 2407.

Exceptions:

  1. For one-and two-family dwellings, only the single concentrated load required by Section 1607A.7.1.1 shall be applied.
  2. In Group I-3, F, H and S occupancies, for areas that are not accessible to the general public and that have an occupant load less than 50, the minimum load shall be 20 pounds per foot (0.29 kN/m).

1607A.7.1.1 Concentrated load. Handrails and guards shall be able to resist a single concentrated load of 200 pounds (0.89 kN), applied in any direction at any point along the top, and to transfer this load through the supports to the structure. This load need not be assumed to act concurrently with the loads specified in Section 1607A.7.1.

1607A.7.1.2 Components. Intermediate rails (all those except the handrail), balusters and panel fillers shall be designed to withstand a horizontally applied normal load of 50 pounds (0.22 kN) on an area equal to 1 square foot (0.093 m2), including openings and space between rails. Reactions due to this loading are not required to be super imposed with those of Section 1607A.7.1 or 1607A.7.1.1.

1607A.7.2 Grab bars, shower seats and dressing room bench seats. Grab bars, shower seats and dressing room bench seat systems shall be designed to resist a single concentrated load of 250 pounds (1.11 kN) applied in any direction

88

at any point. [DSA-AC] See Chapter 11A, Section 1127A.4, and Chapter 11B, Sections 1115B.7.2 and 1117B.8, for grab bars, shower seats and dressing room bench seats, as applicable.

1607A.7.3 Vehicle barrier systems. Vehicle barrier systems for passenger vehicles shall be designed to resist a single load of 6,000 pounds (26.70 kN) applied horizontally in any direction to the barrier system and shall have anchorage or attachment capable of transmitting this load to the structure. For design of the system, two loading conditions shall be analyzed. The first conditions shall apply the load at a height of 1 foot, 6 inches (457 mm) above the floor or ramp surface. The second loading condition shall apply the load at 2 feet, 3 inches (686 mm) above the floor or ramp surface. The more severe load condition shall govern the design of the barrier restraint system. The load shall be assumed to act on an area not to exceed 1 square foot (0.0929 m2), and is not required to be assumed to act concurrently with any handrail or guard loadings specified in Section 1607A.7.1. Garages accommodating trucks and buses shall be designed in accordance with an approved method that contains provisions for traffic railings.

1607A.8 Impact loads. The live loads specified in Section 1607A.3 include allowance for impact conditions. Provisions shall be made in the structural design for uses and loads that involve unusual vibration and impact forces.

1607A.8.1 Elevators. Elevator loads shall be increased by 100 percent for impact and the structural supports shall be designed within the limits of deflection prescribed by ASME A17.1.

1607A.8.2 Machinery. For the purpose of design, the weight of machinery and moving loads shall be increased as follows to allow for impact: (1) elevator machinery, 100 percent; (2) light machinery, shaft-or motor-driven, 20 percent; (3) reciprocating machinery or power-driven units, 50 percent; (4) hangers for floors or balconies, 33 percent. Percentages shall be increased where specified by the manufacturer.

1607A.9 Reduction in live loads. Except for uniform live loads at roofs, all other minimum uniformly distributed live loads, Lo, in Table 1607A.1 are permitted to be reduced in accordance with Section 1607A.9.1 or 1607A.9.2. Roof uniform live loads, other than special purpose roofs of Section 1607A.11.2.2, are permitted to be reduced in accordance with Section 1607A.11.2. Roof uniform live loads of special purpose roofs are permitted to be reduced in accordance with Section 1607A.9.1 or 1607A.9.2.

1607A.9.1 General. Subject to the limitations of Sections 1607A.9.1.1 through 1607A.9.1.4, members for which a value of KLLAT is 400 square feet (37.16 m2) or more are permitted to be designed for a reduced live load in accordance with the following equation:

Image

where:

L = Reduced design live load per square foot (meter) of area supported by the member.

Lo = Unreduced design live load per square foot (meter) of area supported by the member (see Table 1607A.1).

KLL = Live load element factor (see Table 1607A.9.1).

AT = Tributary area, in square feet (square meters).

L shall not be less than 0.50Lo for members supporting one floor and L shall not be less than 0.40Lo for members supporting two or more floors.

TABLE 1607A.9.1
LIVE LOAD ELEMENT FACTOR, KLL
ELEMENTKLL
Interior Columns
Exterior columns without cantilever slabs		4
4
Edge columns with cantilever slabs4
Corner columns with cantilever slabs
Edge beams without cantilever slabs
Interior beams		2
2
2
All other members not identified above including:
Edge beams with cantilever slabs
Cantilever beams
One-way slabs
Two-way slabs
Members without provisions for continuous shear
transfer normal to their span		1

1607A.9.1.1 One-way slabs. The tributary area, AT, for use in Equation 16A-22 for one-way slabs shall not exceed an area defined by the slab span times a width normal to the span of 1.5 times the slab span.

1607A.9.1.2 Heavy live loads. Live loads that exceed 100 psf (4.79 kN/m2) shall not be reduced.

Exceptions:

  1. The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607A.9.1.
  2. For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.

1607A.9.1.3 Passenger vehicle garages. The live loads shall not be reduced in passenger vehicle garages.

Exception: The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent, but the live load shall not be less than L as calculated in Section 1607A.9.1.

1607A.9.1.4 Group A occupancies. Live loads of 100 psf (4.79 kN/m2) and at areas where fixed seats are located shall not be reduced in Group A occupancies.

1607A.9.1.5 Roof members. Live loads of 100 psf (4.79 kN/m2) or less shall not be reduced for roof members except as specified in Section 1607A.11.2.

89

1607A.9.2 Alternate floor live load reduction. As an alternative to Section 1607A.9.1, floor live loads are permitted to be reduced in accordance with the following provisions. Such reductions shall apply to slab systems, beams, girders, columns, piers, walls and foundations.

  1. A reduction shall not be permitted in Group A occupancies.
  2. A reduction shall not be permitted where the live load exceeds 100 psf(4.79kN/m2) except that the design live load for members supporting two or more floors is permitted to be reduced by 20 percent.

    Exception: For uses other than storage, where approved, additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.

  3. A reduction shall not be permitted in passenger vehicle parking garages except that the live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent.
  4. For live loads not exceeding 100 psf (4.79 kN/m2), the design live load for any structural member supporting 150 square feet (13.94 m2) or more is permitted to be reduced in accordance with Equation 16A-23.
  5. For one-way slabs, the area, A, for use in Equation 16A-23 shall not exceed the product of the slab span and a width normal to the span of 0.5 times the slab span.

Image

For SI: R = 0.861 (A - 13.94)

Such reduction shall not exceed the smallest of:

  1. 40 percent for horizontal members;
  2. 60 percent for vertical members; or
  3. R as determined by the following equation.

Image

where:

A = Area of floor supported by the member, square feet (m2).

D = Dead load per square foot (m2) of area supported.

Lo = Unreduced live load per square foot (m2) of area supported.

R = Reduction in percent.

1607A.10 Distribution of floor loads. Where uniform floor live loads are involved in the design of structural members arranged so as to create continuity, the minimum applied loads shall be the full dead loads on all spans in combination with the floor live loads on spans selected to produce the greatest effect at each location under consideration. It shall be permitted to reduce floor live loads in accordance with Section 1607A.9.

1607A.11 Roof loads. The structural supports of roofs and marquees shall be designed to resist wind and, where applicable, snow and earthquake loads, in addition to the dead load of construction and the appropriate live loads as prescribed in this section, or as set forth in Table 1607A.1. The live loads acting on a sloping surface shall be assumed to act vertically on the horizontal projection of that surface.

1607A.11.1 Distribution of roof loads. Where uniform roof live loads are reduced to less than 20 psf (0.96 kN/m2) in accordance with Section 1607A.11.2.1 and are applied to the design of structural members arranged so as to create continuity, the reduced roof live load shall be applied to adjacent spans or to alternate spans, whichever produces the most unfavorable load effect. See Section 1607A.11.2 for reductions in minimum roof live loads and Section 7.5 of ASCE 7 for partial snow loading.

1607A.11.2 Reduction in roof live loads. The minimum uniformly distributed live loads of roofs and marquees, Lo, in Table 1607A.1 are permitted to be reduced in accordance with Section 1607A.11.2.1 or 1607A.11.2.2.

1607A.11.2.1 Flat, pitched and curved roofs. Ordinary flat, pitched and curved roofs, and awnings and canopies other than of fabric construction supported by lightweight rigid skeleton structures, are permitted to be designed for a reduced roof live load as specified in the following equations or other controlling combinations of loads in Section 1605A, whichever produces the greater load.

In structures such as greenhouses, where special scaffolding is used as a work surface for workers and materials during maintenance and repair operations, a lower roof load than specified in the following equations shall not be used unless approved by the building official. Such structures shall be designed for a minimum roof live load of 12 psf (0.58 kN/m2).

Image

where: 12≤Lr≤20

For SI: Lr = LoR1R2

where: 0.58≤Lr≤0.96

Lr = Reduced live load per square foot (m2) of horizontal projection in pounds per square foot (kN/m2).

The reduction factors R1 and R2 shall be determined as follows:

Image

Image

For SI: 1.2–0.011At for 18.58 square meters At55.74 square meters

Image

where:

At = Tributary area (span length multiplied by effective width) in square feet (m2) supported by any structural member, and

Image

90

Image

where:

F = For a sloped roof, the number of inches of rise per foot (for SI:F = 0.12×slope, with slope expressed as a percentage), or for an arch or dome, the rise-to-span ratio multiplied by 32.

1607A.11.2.2 Special-purpose roofs. Roofs used for promenade purposes, roof gardens, assembly purposes or other special purposes, and marquees, shall be designed for a minimum live load, Lo, as specified in Table 1607A.1. Such live loads are permitted to be reduced in accordance with Section 1607A.9. Live loads of 100 psf (4.79 kN/m2) or more at areas of roofs classified as Group A occupancies shall not be reduced.

1607A.11.3 Landscaped roofs. Where roofs are to be landscaped, the uniform design live load in the landscaped area shall be 20 psf (0.958 kN/m2). The weight of the landscaping materials shall be considered as dead load and shall be computed on the basis of saturation of the soil.

1607A.11.4 Awnings and canopies. Awnings and canopies shall be designed for uniform live loads as required in Table 1607A.1 as well as for snow loads and wind loads as specified in Sections 1608A and 1609A.

1607A.11.5 Uncovered open-frame roof structures. Uncovered open-frame roof structures shall be designed for a vertical live load of not less than 10 pounds per square foot (0.48 kN/m2) of the total area encompassed by the framework.

1607A.12 Crane loads. The crane live load shall be the rated capacity of the crane. Design loads for the runway beams, including connections and support brackets, of moving bridge cranes and monorail cranes shall include the maximum wheel loads of the crane and the vertical impact, lateral and longitudinal forces induced by the moving crane.

1607A.12.1 Maximum wheel load. The maximum wheel loads shall be the wheel loads produced by the weight of the bridge, as applicable, plus the sum of the rated capacity and the weight of the trolley with the trolley positioned on its runway at the location where the resulting load effect is maximum.

1607A.12.2 Vertical impact force. The maximum wheel loads of the crane shall be increased by the percentages shown below to determine the induced vertical impact or vibration force:

Monorail cranes (powered)25 percent
Cab-operated or remotely operated bridge cranes (powered)25 percent
Pendant-operated bridge cranes (powered)10 percent
Bridge cranes or monorail cranes with hand-geared bridge, trolley and hoist0 percent

1607A.12.3 Lateral force. The lateral force on crane runway beams with electrically powered trolleys shall be calculated as 20 percent of the sum of the rated capacity of the crane and the weight of the hoist and trolley. The lateral force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction perpendicular to the beam, and shall be distributed according to the lateral stiffness of the runway beam and supporting structure.

1607A.12.4 Longitudinal force. The longitudinal force on crane runway beams, except for bridge cranes with hand-geared bridges, shall be calculated as 10 percent of the maximum wheel loads of the crane. The longitudinal force shall be assumed to act horizontally at the traction surface of a runway beam, in either direction parallel to the beam.

1607A.13 Interior walls and partitions. Interior walls and partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the loads to which they are subjected but not less than a horizontal load of 5 psf (0.240 kN/m2). The 5 psf (0.24 kN/m2) load need not be applied simultaneously with wind or seismic loads. The deflection of such walls under a load of 5 psf (0.24 kN/m2) shall not exceed the limits in Table 1604A.3.

Exception: Fabric partitions complying with Section 1607A.13.1 shall not be required to resist the minimum horizontal load of 5 psf (0.24 kN/m2).

1607A.13.1 Fabric partitions. Fabric partitions that exceed 6 feet (1829 mm) in height, including their finish materials, shall have adequate strength to resist the following load conditions:

  1. A horizontal distributed load of 5 psf (0.24 kN/m2) applied to the partition framing. The total area used to determine the distributed load shall be the area of the fabric face between the framing members to which the fabric is attached. The total distributed load shall be uniformly applied to such framing members in proportion to the length of each member.
  2. A concentrated load of 40 pounds (0.176 kN) applied to an 8-inch diameter (203 mm) area [50.3 square inches (32 452 mm2)] of the fabric face at a height of 54 inches (1372 mm) above the floor.

SECTION 1608A
SNOW LOADS

1608A.1 General. Design snow loads shall be determined in accordance with Chapter 7 of ASCE 7, but the design roof load shall not be less than that determined by Section 1607A.

1608A.2 Ground snow loads. The ground snow loads to be used in determining the design snow loads for roofs shall be determined in accordance with ASCE 7 or Figure 1608A.2 for the contiguous United States. Site-specific case studies shall be made in areas designated “CS” in Figure 1608A.2. Ground snow loads for sites at elevations above the limits indicated in Figure 1608A.2 and for all sites within the CS areas shall be approved. Ground snow load determination for such sites shall be based on an extreme value statistical analysis of data available in the vicinity of the site using a value with a 2-percent annual probability of being exceeded (50-year mean recurrence interval).

1608A.3 Determination of snow loads. [DSA-SS] The ground snow load or the design snow load for roofs shall conform with the adopted ordinance of the city, county, or city and county in which the project site is located, and shall be approved by DSA.

91

FIGURE 1608A.2 GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)

FIGURE 1608A.2
GROUND SNOW LOADS, pg, FOR THE UNITED STATES (psf)

92

FIGURE 1608A.2–continuedGROUND SNOW LOADS, pg FOR THE UNITED STATES (psf)

FIGURE 1608A.2–continued
GROUND SNOW LOADS, pg FOR THE UNITED STATES (psf)

93

SECTION 1609A
WIND LOADS

1609A.1 Applications. Buildings, structures and parts thereof shall be designed to withstand the minimum wind loads prescribed herein. Decreases in wind loads shall not be made for the effect of shielding by other structures.

1609A.1.1 Determination of wind loads. Wind loads on every building or structure shall be determined in accordance with Chapter 6 of ASCE 7 or provisions of the alternate all-heights method in Section 1609A.6. The type of opening protection required, the basic wind speed and the exposure category for a sites is permitted to be determined in accordance with Section 1609A or ASCE 7. Wind shall be assumed to come from any horizontal direction and wind pressures shall be assumed to act normal to the surface considered.

Exceptions:

  1. Subject to the limitations of Section 1609A.1.1.1, the provisions of ICC 600 shall be permitted for applicable Group R-2 and R-3 buildings.
  2. Subject to the limitations of Section 1609A.1.1.1, residential structures using the provisions of the AF&PA WFCM.
  3. Subject to the limitations of Section 1609A.1.1.1, residential structures using the provisions of AISI S230.
  4. Designs using NAAMM FP 1001.
  5. Designs using TIA-222 for antenna-supporting structures and antennas.
  6. Wind tunnel tests in accordance with Section 6.6 of ASCE 7, subject to the limitations in Section 1609A.1.1.2.

1609A.1.1.1 Applicability. The provisions of ICC 600 are applicable only to buildings located within Exposure B or C as defined in Section 1609A.4. The provisions of ICC 600, AF&PA WFCM and AISI S230 shall not apply to buildings sited on the upper half of an isolated hill, ridge or escarpment meeting the following conditions:

  1. The hill, ridge or escarpment is 60 feet (18 288 mm) or higher if located in Exposure B or 30 feet (9144 mm) or higher if located in Exposure C;
  2. The maximum average slope of the hill exceeds 10 percent; and
  3. The hill, ridge or escarpment is unobstructed upwind by other such topographic features for a distance from the high point of 50 times the height of the hill or 1 mile (1.61 km), whichever is greater.

1609A.1.1.2 Wind tunnel test limitations. The lower limit on pressures for main wind-force-resisting systems and components and cladding shall be in accordance with Sections 1609A.1.1.2.1 and 1609A.1.1.2.2.

1609A.1.1.2.1 Lower limits on main wind-force-resisting system. Base overturning moments determined from wind tunnel testing shall be limited to not less than 80 percent of the design base overturning moments determined in accordance with Section 6.5 of ASCE 7, unless specific testing is performed that demonstrates it is the aerodynamic coefficient of the building, rather than shielding from other structures, that is responsible for the lower values. The 80-percent limit shall be permitted to be adjusted by the ratio of the frame load at critical wind directions as determined from wind tunnel testing without specific adjacent buildings, but including appropriate upwind roughness, to that determined in Section 6.5 of ASCE 7.

1609A.1.1.2.2 Lower limits on components and cladding. The design pressures for components and cladding on walls or roofs shall be selected as the greater of the wind tunnel test results or 80 percent of the pressure obtained for Zone 4 for walls and Zone 1 for roofs as determined in Section 6.5 of ASCE 7, unless specific testing is performed that demonstrates it is the aerodynamic coefficient of the building, rather than shielding from nearby structures, that is responsible for the lower values. Alternatively, limited tests at a few wind directions without specific adjacent buildings, but in the presence of an appropriate upwind roughness, shall be permitted to be used to demonstrate that the lower pressures are due to the shape of the building and not to shielding.

1609A.1.1.3 Special wind regions. [DSA-SS] The basic wind speed for projects located in special wind regions as defined in Figure 1609A shall conform with the adopted ordinance of the city, county or city and county in which the project site is located, and shall be approved by DSA-SS.

1609A.1.2 Protection of openings. In wind-borne debris regions, glazing in buildings shall be impact resistant or protected with an impact-resistant standard or ASTM E 1996 and ASTM E 1886 referenced herein as follows:

  1. Glazed openings located within 30 feet (9144 mm) of grade shall meet the requirements of the large missile test of ASTM E 1996.
  2. Glazed openings located more than 30 feet (9144 mm) above grade shall meet the provisions of the small missile test of ASTM E 1996.

Exceptions:

  1. Wood structural panels with a minimum thickness of 7/16 inch (11.1 mm) and maximum panel span of 8 feet (2438 mm) shall be permitted for opening protection in one- and two-story buildings classified as Group R-3 or R-4 occupancy. Panels shall be precut so that they shall be attached to the framing surrounding the opening containing the product with the glazed opening. Panels shall be predrilled as required for the anchorage method and shall be secured with the attachment hardware provided. Attachments shall be designed to resist 94 the components and cladding loads determined in accordance with the provisions of ASCE 7, with corrosion-resistant attachment hardware provided and anchors permanently installed on the building. Attachment in accordance with Table 1609A. 1.2 with corrosion-resistant attachment hardware provided and anchors permanently installed on the building is permitted for buildings with a mean roof height of 45 feet (13 716 mm) or less where wind speeds do not exceed 140 mph (63 m/s).
  2. Glazing in Occupancy Category I buildings as defined in Section 1604A.5, including greenhouses that are occupied for growing plants on a production or research basis, without public access shall be permitted to be unprotected.
  3. Glazing in Occupancy Category II, III or IV buildings located over 60 feet (18 288 mm) above the ground and over 30 feet (9144 mm) above aggregate surface roofs located within 1,500 feet (458 m) of the building shall be permitted to be unprotected.

1609A.1.2.1 Louvers. Louvers protecting intake and exhaust ventilation ducts not assumed to be open that are located within 30 feet (9144 mm) of grade shall meet requirements of an approved impact-resisting standard or the large missile test of ASTM E 1996.

1609A.1.2.2 Garage doors. Garage door glazed opening protection for wind-borne debris shall meet the requirements of an approved impact-resisting standard or ANSI/DASMA 115.

1609A.1.3 Story drift for wind loads. The calculated story drift due to wind pressures shall not exceed 0.005 times the story height for buildings less than 65 feet (19 812 mm) in height or 0.004 times the story height for buildings 65 feet (19 812 mm) or greater in height.

1609A.2 Definitions. The following words and terms shall, for the purposes of Section 1609A, have the meanings shown herein.

TABLE 1609A.1.2
WIND-BORNE DEBRIS PROTECTION FASTENING SCHEDULE FOR WOOD STRUCTURAL PANELSa, b, c, d
FASTENER TYPEFASTENER SPACING (inches)
Panel Span ≤ 4 feet4 feet < Panel Span ≤ 6 feet6 feet < Panel Span ≤ 8 feet
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N, 1 mile per hour = 0.447 m/s.
a. This table is based on 140 mph wind speeds and a 45-foot mean roof height.
b. Fasteners shall be installed at opposing ends of the wood structural panel. Fasteners shall be located a minimum of 1 inch from the edge of the panel.
c. Anchors shall penetrate through the exterior wall covering with an embedment length of 2 inches minimum into the building frame. Fasteners shall be located a minimum of 2½ inches from the edge of concrete block or concrete.
d. Where panels are attached to masonry or masonry/stucco, they shall be attached using vibration-resistant anchors having a minimum ultimate withdrawal capacity of 1,500 pounds.
No.8 wood-screw-based anchor with 2-inch embedment length16108
No. 10 wood-screw-based anchor with 2-inch embedment length16129
¼-inch diameter lag-screw-based anchor with 2-inch embedment length161616

HURRICANE-PRONE REGIONS. Areas vulnerable to hurricanes defined as:

  1. The U.S. Atlantic Ocean and Gulf of Mexico coasts where the basic wind speed is greater than 90 mph (40 m/s) and
  2. Hawaii, Puerto Rico, Guam, Virgin Islands and American Samoa.

WIND-BORNE DEBRIS REGION. Portions of hurricane-prone regions that are within 1 mile (1.61 km) of the coastal mean high water line where the basic wind speed is 110 mph (48 m/s) or greater; or portions of hurricane-prone regions where the basic wind speed is 120 mph (53 m/s) or greater; or Hawaii.

TABLE 1609A.3.1
EQUIVALENT BASIC WIND SPEEDSa, b, c
For SI: 1 mile per hour = 0.44 m/s.
a. Linear interpolation is permitted.
b. V3s is the 3-second gust wind speed (mph).
c. Vfm is the fastest mile wind speed (mph).
V3s8590100105110120125130140145150160170
Vfm7176859095104109114123128133142152
95

FIGURE 1609 A BASIC WIND SPEED (3-SECOND GUST)

FIGURE 1609 A
BASIC WIND SPEED (3-SECOND GUST)

96

1609A.3 Basic wind speed. The basic wind speed, in mph, for the determination of the wind loads shall be determined by Figure 1609A. Basic wind speed for the special wind regions indicated, near mountainous terrain and near gorges shall be in accordance with local jurisdiction requirements. Basic wind speeds determined by the local jurisdiction shall be in accordance with Section 6.5.4 of ASCE 7.

In nonhurricane-prone regions, when the basic wind speed is estimated from regional climatic data, the basic wind speed shall be not less than the wind speed associated with an annual probability of 0.02 (50-year mean recurrence interval), and the estimate shall be adjusted for equivalence to a 3-second gust wind speed at 33 feet (10 m) above ground in Exposure Category C. The data analysis shall be performed in accordance with Section 6.5.4.2 of ASCE 7.

1609A.3.1 Wind speed conversion. When required, the 3-second gust basic wind speeds of Figure 1609A shall be converted to fastest-mile wind speeds, Vfm’ using Table 1609A.3.1 or Equation 16A-32.

Image

where:

V3S = 3-second gust basic wind speed from Figure 1609.A.

1609A.4 Exposure category. For each wind direction considered, and exposure category that adequately reflects the characteristics of ground surface irregularities shall be determined for the site at which the building or structure is to be constructed. Account shall be taken of variations in ground surface roughness that arise from natural topography and vegetation as well as from constructed features.

1609A.4.1 Wind directions and sectors. For each selected wind direction at which the wind loads are to be evaluated, the exposure of the building or structure shall be determined for the two upwind sectors extending 45 degrees (0.79 rad) either side of the selected wind direction. The exposures in these two sectors shall be determined in accordance with Sections 1609A.4.2 and 1609A.4.3 and the exposure resulting in the highest wind loads shall be used to represent winds from that direction.

1609A.4.2 Surface roughness categories. A ground surface roughness within each 45-degree (0.79 rad) sector shall be determined for a distance upwind of the site as defined in Section 1609A.4.3 from the categories defined below, for the purpose assigning an exposure category as defined in Section 1609A.4.3.

Surface Roughness categories. A ground surface roughness within each 45-degree (0.79 rad) sector shall be determined for a distance upwind of the site as defined in Section 1609A.4.3 from the categories defined below, for the purpose of assigning an exposure category as defined in Section 1609A.4.3.

Surface Roughness B. Urban and suburban areas, wooded other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.

Surface Roughness C. Open terrain with scattered obstructions having heights generally less than 30 feet (9144 mm). This category includes flat open country, grasslands, and all water surface in hurricane-prone regions.

Surface Roughness D. Flat, unobstructed areas and water surfaces outside hurricane-prone regions. This category includes smooth mud flats, salt flats and unbroken ice.

1609A.4.3 Exposure categories. An exposure category shall be determined in accordance with the following:

Exposure B. Exposure B shall apply where the ground surface roughness condition, as defined by Surface Roughness B, prevails in the upwind direction for a distance of at least 2,600 feet (792 m) or 20 times the height of the building, whichever is greater.

Exception: For buildings whose mean roof height is less than or equal to 30 feet (9144 mm), the upwind distance is permitted to be reduced to 1,500 feet (457 m).

Exposure C. Exposure C shall apply for all cases where Exposures B or D do not apply.

Exposure D. Exposure D shall apply where the ground surface roughness, as defined by Surface Roughness D, prevails in the upwind direction for a distance of at least 5,000 feet (1524 m) or 20 times the height of the building, whichever is greater. Exposure D shall extend inland from the shoreline for a distance of 600 feet (183 m) or 20 times the height of the building, whichever is greater.

1609A.5 Roof systems.

1609 A.5.1 Roof deck. The roof deck shall be designed to withstand the wind pressures determined in accordance with ASCE 7.

1609A.5.2 Roof coverings. Roof coverings shall comply with Section 1609A.5.1.

Exception: Rigid tile roof coverings that are air permeable and installed over a roof deck complying with Section 1609A.5.1 are permitted to be designed in accordance with Section 1609A.5.3.

Asphalt shingles installed over a roof deck complying with Section 1609A.5.1 Shall comply with the wind-resistance requirements of Section 1507.2.7.1.

1609A.5.3 Rigid tile. Wind loads on rigid tile roof coverings shall be determined in accordance with the following equation:

Image

where:

b = Exposed width, feet (mm) of the roof tile.

CL = Lift coefficient. The lift coefficient for concrete and clay tile shall be 0.2 or shall be determined by test in accordance with Section 1716.2.

GCp = Roof pressure coefficient for each applicable roof zone determined from Chapter 6 of ASCE 7. Roof coefficients shall not be adjusted for internal pressure.

97

L = Length, feet (mm) of the roof tile.

La = Moment arm, feet (mm) from the axis of rotation to the point of uplift on the roof tile. The point of uplift shall be taken at 0.76L from the head of the tile and the middle of the exposed width. For roof tiles with nails or screws (with or without a tail clip), the axis of rotation shall be taken as the head of the tile for direct deck application or as the top edge of the batten for battened applications. For roof tiles fastened only by a nail or screw along the side of the tile, the axis of rotation shall be determined by testing. For roof tiles installed with battens and fastened only by a clip near the tail of the tile, the moment arm shall be determined about the top edge of the batten with consideration given for the point of rotation of the tiles based on straight bond or broken bond and the tile profile.

Ma = Aerodynamic uplift moment, feet-pounds (N-mm) acting to raise the tail of the tile.

qh = Wind velocity pressure, psf (kN/m2) determined from Section 6.5.10 of ASCE 7.

Concrete and clay roof tiles complying with the following limitations shall be designed to withstand the aerodynamic uplift moment as determined by this section.

  1. The roof tiles shall be either loose laid on battens, mechanically fastened, mortar set of adhesive set.
  2. The roof tiles shall be installed on solid sheathing which has been designed as components and cladding.
  3. An underlayment shall be installed in accordance with Chapter 15.
  4. The tile shall be single lapped interlocking with a minimum head lap of not less than 2 inches (51 mm).
  5. The length of the tile shall be between 1.0 and 1.75 feet (305 mm and 533 mm).
  6. The exposed width of the tile shall be between 0.67 and 1.25 feet (204 mm and 381 mm).
  7. The maximum thickness of the tail of the tile shall not exceed 1.3 inches (33 mm).
  8. Roof tiles using mortar set or adhesive set systems shall have at least two-thirds of the tile’s area free of mortar or adhesive contact.

1609.A.6 Alternate all-heights method. The alternate wind design provisions in this section are simplifications of the ASCE 7 Method 2—Analytical Procedure.

1609A.6.1 Scope. As an alternative to ASCE 7 Section 6.5, the following provisions are permitted to be used to determine the wind effects on regularly shaped buildings, or other structures that are regularly shaped, which meet all of the following conditions:

  1. The building or other structure is less than or equal to 75 feet (22 860 mm) in height with a height-to-least-width ratio of 4 or less, or the building or other structure has a fundamental frequency greater than or equal to 1 hertz.
  2. The building or other structure is not sensitive to dynamic effects.
  3. The building or other structure is not located on a site for which channeling effects or buffeting in the wake of upwind obstructions warrant special consideration.
  4. The building shall meet the requirements of a simple diaphragm building as defined in ASCE 7 Section 6.2, where wind loads are only transmitted to the main wind-force-resisting system (MWFRS) at the diaphragms.
  5. For open buildings, multispan gable roofs, stepped roofs, sawtooth roofs, domed roofs, roofs with slopes greater than 45 degrees (0.79 rad), solid free-standing walls and solid signs, and rooftop equipment, apply ASCE 7 provisions.

1609A.6.1.1 Modifications. The following modifications shall be made to certain subsections in ASCE 7: in Section 1609A.6.2, symbols and notations that are specific to this section are used in conjunction with the symbols and notations in ASCE 7 Section 6.3.

1609A.6.2 Symbols and notations. Coefficients and variables used in the alternative all-heights method equations are as follows:

Cnet = Net-pressure coefficient based on Kd [(G) (Cp)– (GCpi)], in accordance with Table 1609A.6.2(2).

G = Gust effect factor for rigid structures in accordance with ASCE 7 Section 6.5.8.1.

I = Importance Factor in accordance with ASCE 7 Section 6.5.5

Kd = Wind directionality factor in accordance with ASCE 7 Table 6-4.

pnet = Design wind pressure to be used in determination of wind loads on buildings or other structures or their components and cladding, in psf (kN/m2).

qs = Wind stagnation pressure in psf (kN/m2) in accordance with Table 1609A.6.2(1).

TABLE 1609A.6.2(1)
WIND VELOCITY PRESSURE (qs) AT STANDARD HEIGHT OF 33 FEETa
For SI: 1 foot = 304.8 mm, 1 mph = 0.44 m/s, 1 psf = 47.88 P a.
a. For basic wind speeds not shown, use qs = 0.00256 V2.
BASIC WIND SPEED (mph)8590100105110120125130140150160170
PRESSURE, qs(psf)18.520.725.628.231.036.940.043.350.257.665.574.0
98
TABLE 1609A.6.2(2)
NET PRESSURE COEFFICIENTS, Cneta, b
STRUCTURE OR PART THEREOFDESCRIPTIONCnetFACTOR
For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929m2, 1 degree = 0.0175 rad.
a. Linear interpolation between values in the table is permitted.
b. Some Cnet values have been grouped together, Less conservative results may be obtained by applying ASCE 7 provisions.
1. Main wind force-resisting frames and systemsWalls:EnclosedPartially enclosed
+Internal pressure-Internal pressure+Internal pressure-Internal pressure
Windward wall0.430.730.111.05
Leeward wall-0.51-0.21-0.830.11
Sidewall-0.66-0.35-0.97-0.04
Parapet wallWindward1.281.28
Leeward-0.85-0.85
Roofs:EnclosedPartially enclosed
Wind perpendicular to ridge+Internal pressure-Internal pressure+Internal pressure-Internal pressure
Leeward roof or flat roof-0.66-0.35-0.97-0.04
Windward roof slopes:
Slope < 2:12 (10°)Condition 1-1.09-0.79-1.41-0.47
Condition 2-0.280.02-0.600.34
Slope = 4:12 (18°)Condition 1-0.73-0.42-1.04-0.11
Condition 2-0.050.25-0.370.57
Slope = 5:12 (23°)Condition 1-0.58-0.28-0.900.04
Condition 20.030.34-0.290.65
Slope = 6:12 (27°)Condition 1-0.47-0.16-0.780.15
Condition 20.060.37-0.250.68
Slope = 7:12 (30°)Condition 1-0.37-0.06-0.680.25
Condition 20.070.37-0.250.69
Slope = 9:12 (37°)Condition 1-0.270.04-0.580.35
Condition 20.140.44-0.180.76
Slope 12:12 (45°)0.140.44-0.180.76
Wind parallel to ridge and flat roofs-1.09-0.79-1.41-0.47
Nonbuilding Structures: Chimneys, Tanks and Similar Structures:
 h/D
1725
Square (Wind normal to face)0.991.071.53
Square (Wind on diagonal)0.770.841.15
Hexagonal or Octagonal0.810.971.13
Round0.650.810.97
Open signs and lattice frameworksRatio of solid to gross area
 <0.10.1 to 0.290.3 to 0.7
Flat1.451.301.16
Round0.870.941.08
2. Components and cladding not in areas of discontinuity—roofs and overhangs
Gable of hipped configurations (Zone 1)
Flat < Slope < 6:12 (27°) See ASCE 7 Figure 6-11C Zone 1
Positive10 square feet or less0.580.89
100 square feet or more0.410.72
Negative10 square feet or less-1.00-1.32
100 square feet or more-0.92-1.23
Overhang: Flat < Slope < 6:12 (27°) See ASCE 7 Figure 6-11B Zone 1
Negative10 square feet or less-1.45
100 square feet or more-1.36
500 square feet or more-0.94
6:12 (27°) < Slope < 12:12 (45°) See ASCE 7 Figure 6-11D Zone 1
Positive10 square feet or less0.921.23
100 square feet or more0.831.15
Negative10 square feet or less-1.00-1.32
100 square feet or more-0.83-1.15
Monosloped configurations (Zone 1)EnclosedPartially enclosed
Flat < Slope < 7:12 (30°) See ASCE 7 Figure 6-14B Zone 1
Positive10 square feet or less0.490.81
100 square feet or more0.410.72
Negative10 square feet or less-1.26-1.57
100 square feet or more-1.09-1.40
Tall flat-topped roofs h ‹ 60EnclosedPartially enclosed
Flat < Slope < 2:12 (10°) (Zone 1) See ASCE 7 Figure 6-17 Zone 1
Negative10 square feet or less-1.34-1.66
500 square feet or more-0.92-1.23
3. Components and cladding in areas of discontinuity—roofs and overhangsRoof elements and slopesEnclosedPartially enclosed
Gable or hipped configurations at ridges, eaves and rakes (Zone 2)
Flat < Slope < 6: 12 (27°) See ASCE 7 Figure 6-11 C Zone 2
Positive10 square feet or less0.580.89
100 square feet or more0.4110.72
Negative10 square feet or less-1.68-2.00
100 square feet or more-1.17-1.49
Overhang for Slope Flat < Slope < 6:12 (27°) See ASCE 7 Figure 6-11C Zone 3
Negative10 square feet or less-1.87
100 square feet or more-1.87
6:12 (27°) < 12:12 (45°) See ASCE 7 Figure 6-11DEnclosedPartially enclosed
Positive10 square feet or less0.921.23
100 square feet or more0.831.15
Negative10 square feet or less-1.17-1.49
100 square feet or more-1.00-1.32
Overhang for 6:12 (27°) < Slope < 12:12 (45°) See ASCE 7 Figure 6-11D Zone2
Negative10 square feet or less-1.70
500 square feet or more-1.53
Monosloped configurations at ridges, eaves and rakes (Zone 2)
Flat < Slope < 7:12 (30°) See ASCE 7 Figure 6-14B Zone 2
Positive10 square feet or less0.490.81
100 square feet or more0.410.72
Negative10 square feet or less-1.51-1.83
100 square feet or more-1.43-1.74
Tall flat topped roofs h > 60′EnclosedPartially enclosed
Flat < Slope < 2:12 (10°) (Zone 3) See ASCE 7 Figure 6-17 Zone 2
Negative10 square feet or less-2.11-2.42
500 square feet or more-1.51-1.83
Gable or hipped configurations at comers (Zone 3) See ASCE 7 Figure 6-11 C Zone 3
Flat < Slope < 6:12 (27°)EnclosedPartially enclosed
Positive10 square feet or less0.580.89
100 square feet or more0.410.72
Negative10 square feet or less-2.53-2.85
100 square feet or more-1.85-2.17
Overhang for Slope Flat < Slope < 6: 12 (27°) See ASCE 7 Figure 6-11 C Zone 3
Negative10 square feet or less-3.15
100 square feet or more-2.13
6:12 (27°) < 12:12 (45°) See ASCE 7 Figure 6-11D Zone 3
Positive10 square feet or less0.921.23
100 square feet or more0.831.15
Negative10 square feet or less-1.17-1.49
100 square feet or more-1.00-1.32
Overhang for 6:12 (27°) < Slope < 12:12 (45°)EnclosedPartially enclosed
Negative10 square feet or less-1.70
100 square feet or more-1.53
Monosloped Configurations at corners (Zone 3) See ASCE 7 Figure 6-14B Zone 3
Flat < Slope < 7: 12 (30°)
Positive10 square feet or less0.490.81
100 square feet or more0.410.72
Negative10 square feet or less-2.62-2.93
100 square feet or more-1.85-2.17
Tall flat topped roofs h > 60'EnclosedPartially enclosed
Flat < Slope < 2:12 (10°) (Zone 3) See ASCE 7 Figure 6-17 Zone 3
Negative10 square feet or less-2.87-3.19
500 square feet or more-2.11-2.42
4. Components and cladding not in areas of discontinuity-walls d parapetsWall Elements: h = 60' (Zone 4) Figure 6-11AEnclosedPartially enclosed
Positive10 square feet or less1.001.32
500 square feet or more0.751.06
Negative10 square feet or less-1.09-1.40
500 square feet or more-0.83-1.15
Wall Elements: h > 60' (Zone 4) See ASCE 7 Figure 6-17 Zone 4
Positive20 square feet or less0.921.23
500 square feet or more0.660.98
Negative20 square feet or less-0.92-1.23
500 square feet or more-0.75-1.06
Parapet Walls
Positive2.873.19
Negative-1.68-2.00
5. Components and cladding in areas of discontinuity-walls and parapetsWall elements: h > 60' (Zone 5) Figure 6-11AEnclosedPartially enclosed
Positive10 square feet or less1.001.32
500 square feet or more0.751.06
Negative10 square feet or less-1.34-1.66
500 square feet or more-0.83-1.15
Wall elements: h > 60' (Zone 5) See ASCE 7 Figure 6-17 Zone 4
Positive20 square feet or less0.921.23
500 square feet or more0.660.98
Negative20 square feet or less-1.68-2.00
500 square feet or more-1.00-1.32
Parapet walls
Positive3.643.95
Negative-2.45-2.76
101 102

1609A.6.3 Design equations. When using the alternative all-heights method, the MWFRS, and components and cladding of every structure shall be designed to resist the effects of wind pressures on the building envelope in accordance with Equation 16A-34.

Image

Design wind forces for the MWFRS shall not be less than 10 psf (0.48 kN/m2) multiplied by the area of the structure projected on a plane normal to the assumed wind direction (see ASCE 7 Section 6.1.4 for criteria). Design net wind pressure for components and cladding shall not be less than 10 psf (0.48 kN/m2) acting in either direction normal to the surface.

1609A.6.4 Design procedure. The MWFRS and the components and cladding of every building or other structure shall be designed for the pressures calculated using Equation 16A-34.

1609A.6.4.1 Main wind-force-resisting systems. The MWFRS shall be investigated for the torsional effects identified in ASCE 7 Figure 6-9.

1609A.6.4.2 Determination of Kz and Kzt. Velocity pressure exposure coefficient, Kz’ shall be determined in accordance with ASCE 7 Section 6.5.6.6 and the topographic factor, Kzt’ shall be determined in accordance with ASCE 7 Section 6.5.7.

  1. For the windward side of a structure, Kzt and Kz shall be based on height z.
  2. For leeward and sidewalls, and for windward and leeward roofs, Kzt and Kz shall be based on mean roof height h.

1609A.6.4.3 Determination of net pressure coefficients, Cnet. For the design of the MWFRS and for components and cladding, the sum of the internal and external net pressure shall be based on the net pressure coefficient, Cnet.

  1. The pressure coefficient, Cnet’ for walls and roofs shall be determined from Table 1609A.6.2(2).
  2. Where Cnet has more than one value, the more severe wind load condition shall be used for design.

1609A.6.4.4 Application of wind pressures. When using the alternative all-heights method, wind pressures shall be applied simultaneously on, and in a direction normal to, all building envelope wall and roof surfaces.

1609A.6.4.4.1 Components and cladding. Wind pressure for each component or cladding element is applied as follows using Cnet values based on the effective wind area, A, contained within the zones in areas of discontinuity of width and/or length “a,” “2a” or “4a” at: corners of roofs and walls; edge strips for ridges, rakes and eaves; or field areas on walls or roofs as indicated in figures in tables in ASCE 7 as referenced in Table 1609A.6.2(2) in accordance with the following:

  1. Calculated pressures at local discontinuities acting over specific edge strips or corner boundary areas.
  2. Include “field” (Zone 1, 2 or 4, as applicable) pressures applied to areas beyond the boundaries of the areas of discontinuity.
  3. Where applicable, the calculated pressures at discontinuities (Zones 2 or 3) shall be combined with design pressures that apply specifically on rakes or eave overhangs.103
TABLE 1610A.1
LATERAL SOIL LOAD
DESCRIPTION OF BACKFILL MATERIALcUNIFIED SOIL
CLASSIFICATION		DESIGN LATERAL SOIL LOADa
(pound per square foot per foot of depth)
Active pressureAt-rest pressure
For SI: 1 pound per square foot per foot of depth = 0.157 kPa/m, 1 foot = 304.8 mm.
a. Design lateral soil loads are given for moist conditions for the specified soils at their optimum densities. Actual field conditions shall govern. Submerged or saturated soil pressures shall include the weight of the buoyant soil plus the hydrostatic loads.
b. Unsuitable as backfill material.
c. The definition and classification of soil materials shall be in accordance with ASTM D 2487.
Well-graded, clean gravels; gravel-sand mixesGW3060
Poorly graded clean gravels; gravel-sand mixesGP3060
Silty gravels, poorly graded gravel-sand mixesGM4060
Clayey gravels, poorly graded gravel-and-clay mixesGC4560
Well-graded, clean sands; gravelly sand mixesSW3060
Poorly graded, clean sands; sand-gravel mixesSP3060
Silty sands, poorly graded sand-silt mixesSM4560
Sand-silt clay mix with plastic finesSM-SC45100
Clayey sands, poorly graded sand-clay mixesSC60100
Inorganic silts and clayey siltsML45100
Mixture of inorganic silt and clayML-CL60100
Inorganic clays of low to medium plasticityCL60100
Organic silts and silt clays, low plasticityOLNote bNote b
Inorganic clayey silts, elastic siltsMHNote bNote b
Inorganic clays of high plasticityCHNote bNote b
Organic clays and silty claysOHNote bNote b

SECTION 1610A
SOIL LATERAL LOADS

1610A.1 General. Foundation walls and retaining walls shall be designed to resist lateral soil loads. Soil loads specified in Table 1610A.1 shall be used as the minimum design lateral soil loads unless determined otherwise by a geotechnical investigation in accordance with Section 1803A. Foundation walls and other walls in which horizontal movement is restricted at the top shall be designed for at-rest pressure. Retaining walls free to move and rotate at the top shall be permitted to be designed for active pressure. Design lateral pressure from surcharge loads shall be added to the lateral earth pressure load. Design lateral pressure shall be increased if soils at the site are expansive. Foundation walls shall be designed to support the weight of the full hydrostatic pressure of undrained backfill unless a drainage system is installed in accordance with Sections 1805A.4.2 and 1805A.4.3.

Exception: Foundation walls extending not more than 8 feet (2438 mm) below grade and laterally supported at the top by flexible diaphragms shall be permitted to be designed for active pressure.

SECTION 1611A
RAIN LOADS

1611A.1 Design rain loads. Each portion of a roof shall be designed to sustain the load of rainwater that will accumulate on it if the primary drainage system for that portion is blocked plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow. The design rainfall shall be based on the 100-year hourly rainfall rate indicated in Figure 1611A.1 or on other rainfall rates determined from approved local weather data.

Image

For SI: R = 0.0098(ds + dh)

where:

dh = Additional depth of water on the undeflected roof above the inlet of secondary drainage system at its design flow (i.e., the hydraulic head), in inches (mm).

ds = Depth of water on the undeflected roof up to the inlet of secondary drainage system when the primary drainage system is blocked (i.e., the static head), in inches (mm).

R = Rain load on the undeflected roof, in psf (kN/m2). When the phrase “undeflected roof” is used, deflections from loads (including dead loads) shall not be considered when determining the amount of rain on the roof.

104

[P] FIGURE 1611A.1 100-YEAR, 1-HOUR RAINFALL (INCHES) EASTERN UNITED STATES

[P] FIGURE 1611A.1 100-YEAR, 1-HOUR RAINFALL (INCHES) EASTERN UNITED STATES

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

105

[P] FIGURE 1611.A.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) WESTERN UNITED STATES

[P] FIGURE 1611.A.1—continued
100-YEAR, 1-HOUR RAINFALL (INCHES) WESTERN UNITED STATES

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

106

[P] FIGURE 1611A.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) ALASKA

[P] FIGURE 1611A.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) ALASKA

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

107

[P] FIGURE 1611A.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) HAWALL

[P] FIGURE 1611A.1—continued 100-YEAR, 1-HOUR RAINFALL (INCHES) HAWALL

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

108

[P] FIGURE 1611A.1-continued 100-YEAR, 1-HOUR RAINFALL (INCHES) HAWAII

[P] FIGURE 1611A.1-continued 100-YEAR, 1-HOUR RAINFALL (INCHES) HAWAII

For SI: 1 inch = 25.4 mm.

Source: National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

109

1611A.2 Ponding instability. For roofs with a slope less than ¼ inch per foot [1.19 degrees (0.0208 rad)], the design calculations shall include verification of adequate stiffness to preclude progressive deflection in accordance with Section 8.4 of ASCE 7.

1611A.3 Controlled drainage. Roofs equipped with hardware to control the rate of drainage shall be equipped with a secondary drainage system at a higher elevation that limits accumulation of water on the roof above that elevation. Such roofs shall be designed to sustain the load of rainwater that will accumulate on them to the elevation of the secondary drainage system plus the uniform load caused by water that rises above the inlet of the secondary drainage system at its design flow determined from Section 1611A.1. Such roofs shall also be checked for ponding instability in accordance with Section 1611A.2.

SECTION 1612A
FLOOD LOADS

1612A.1 General. Within flood hazard areas as established in Section 1612A.3, all new construction of buildings, structures and portions of buildings and structures, including substantial improvement and restoration of substantial damage to buildings and structures, shall be designed and constructed to resist the effects of flood hazards and flood loads. For buildings that are located in more than one flood hazard area, the provisions associated with the most restrictive flood hazard area shall apply.

1612A.2 Definitions. The following words and terms shall, for the purposes of this section, have the meanings shown herein.

BASE FLOOD. The flood having a 1-percent chance of being equaled or exceeded in any given year.

BASE FLOOD ELEVATION. The elevation of the base flood, including wave height, relative to the National Geodetic Vertical Datum (NGVD), North American Vertical Datum (NAVD) or other datum specified on the Flood Insurance Rate Map (FIRM).

BASEMENT. The portion of a building having its floor subgrade (below ground level) on all sides.

This definition of “Basement” is limited in application to the provisions of Section 1612A (see “Basement” in Section 502.1).

DESIGN FLOOD. The flood associated with the greater of the following two areas:

  1. Area with a flood plain subject to a 1-percent or greater chance of flooding in any year; or
  2. Area designated as a flood hazard area on a community’s flood hazard map, or otherwise legally designated.

DESIGN FLOOD ELEVATION. The elevation of the “design flood,” including wave height, relative to the datum specified on the community’s legally designated flood hazard map. In areas designated as Zone AO, the design flood elevation shall be the elevation of the highest existing grade of the building’s perimeter plus the depth number (in feet) specified on the flood hazard map. In areas designated as Zone AO where a depth number is not specified on the map, the depth number shall be taken as being equal to 2 feet (610 mm).

DRY FLOODPROOFING. A combination of design modifications that results in a building or structure, including the attendant utility and sanitary facilities, being water tight with walls substantially impermeable to the passage of water and with structural components having the capacity to resist loads as identified in ASCE 7.

EXISTING CONSTRUCTION. Any buildings and structures for which the “start of construction” commenced before the effective date of the community’s first flood plain management code, ordinance or standard. “Existing construction” is also referred to as “existing structures.”

EXISTING STRUCTURE. See “Existing construction.”

FLOOD or FLOODING. A general and temporary condition of partial or complete inundation of normally dry land from:

  1. The overflow of inland or tidal waters.
  2. The unusual and rapid accumulation or runoff of surface waters from any source.

FLOOD DAMAGE-RESISTANT MATERIALS. Any construction material capable of withstanding direct and prolonged contact with floodwaters without sustaining any damage that requires more than cosmetic repair.

FLOOD HAZARD AREA. The greater of the following two areas:

  1. The area within a flood plain subject to a 1-percent or greater chance of flooding in any year.
  2. The area designated as a flood hazard area on a community’s flood hazard map, or otherwise legally designated.

FLOOD HAZARD AREA SUBJECT TO HIGH-VELOCITY WAVE ACTION. Area within the flood hazard area that is subject to high-velocity wave action, and shown on a Flood Insurance Rate Map (FIRM) or other flood hazard map as Zone V, VO, VE or V1-30.

FLOOD INSURANCE RATE MAP (FIRM). An official map of a community on which the Federal Emergency Management Agency (FEMA) has delineated both the special flood hazard areas and the risk premium zones applicable to the community.

FLOOD INSURANCE STUDY. The official report provided by the Federal Emergency Management Agency containing the Flood Insurance Rate Map (FIRM), the Flood Boundary and Floodway Map (FBFM), the water surface elevation of the base flood and supporting technical data.

FLOODWAY. The channel of the river, creek or other water-course and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than a designated height.

LOWEST FLOOR. The floor of the lowest enclosed area, including basement, but excluding any unfinished or flood-resistant enclosure, usable solely for vehicle parking, building access or limited storage provided that such enclosure is not built so as to render the structure in violation of this section.

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SPECIAL FLOOD HAZARD AREA. The land area subject to flood hazards and shown on a Flood Insurance Rate Map or other flood hazard map as Zone A, AE, A1-30, A99, AR, AO, AH, V, VO, VE or V1-30.

START OF CONSTRUCTION. The date of issuance for new construction and substantial improvements to existing structures, provided the actual start of construction, repair, reconstruction, rehabilitation, addition, placement or other improvement is within 180 days after the date of issuance. The actual start of construction means the first placement of permanent construction of a building (including a manufactured home) on a site, such as the pouring of a slab or footings, installation of pilings or construction of columns.

Permanent construction does not include land preparation (such as clearing, excavation, grading or filling), the installation of streets or walkways, excavation for a basement, footings, piers or foundations, the erection of temporary forms or the installation of accessory buildings such as garages or sheds not occupied as dwelling units or not part of the main building. For a substantial improvement, the actual “start of construction” means the first alteration of any wall, ceiling, floor or other structural part of a building, whether or not that alteration affects the external dimensions of the building.

SUBSTANTIAL DAMAGE. Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

SUBSTANTIAL IMPROVEMENT. Any repair, reconstruction, rehabilitation, addition or improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either:

  1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the building official and that are the minimum necessary to assure safe living conditions.
  2. Any alteration of a historic structure provided that the alteration will not preclude the structure's continued designation as a historic structure.

1612A.3 Establishment of flood hazard areas. To establish flood hazard areas, the applicable governing authority shall adopt a flood hazard map and supporting data. The flood hazard map shall include, at a minimum, areas of special flood hazard as identified by the Federal Emergency Management Agency's Flood Insurance Study (FIS) adopted by the local authority having jurisdiction where the project is located, asamended or revised with the accompanying Flood Insurance Rate Map (FIRM) and Flood Boundary and Floodway Map (FBFM) and related supporting data along with any revisions thereto. The adopted flood hazard map and supporting data are hereby adopted by reference and declared to be part of this section.

1612A.3.1 Design flood elevations. Where design flood elevations are not included in the flood hazard areas established in Section 1612A.3, or where floodways are not designated, the building official is authorized to require the applicant to:

  1. Obtain and reasonably utilize any design flood elevation and floodway data available from a federal, state or other source; or
  2. Determine the design flood elevation and/or floodway in accordance with accepted hydrologic and hydraulic engineering practices used to define special flood hazard areas. Determinations shall be undertaken by a registered design professional who shall document that the technical methods used reflect currently accepted engineering practice.

1612A.3.2 Determination of impacts. In riverine flood hazard areas where design flood elevations are specified but floodways have not been designated, the applicant shall provide a floodway analysis that demonstrates that the proposed work will not increase the design flood elevation more than 1 foot (305 mm) at any point within the jurisdiction of the applicable governing authority.

1612A.4 Design and construction. The design and construction of buildings and structures located in flood hazard areas, including flood hazard areas subject to high-velocity wave action, shall be in accordance with Chapter 5 of ASCE 7 and with ASCE 24.

1612A.5 Flood hazard documentation. The following documentation shall be prepared and sealed by a registered design professional and submitted to the building official:

  1. For construction in flood hazard areas not subject to high-velocity wave action:
    1. The elevation of the lowest floor, including the basement, as required by the lowest floor elevation inspection in Section 110.3.3.
    2. For fully enclosed areas below the design flood elevation where provisions to allow for the automatic entry and exit of floodwaters do not meet the minimum requirements in Section 2.6.2.1 of ASCE 24, construction documents shall include a statement that the design will provided for equalization of hydrostatic flood forces in accordance with Section 2.6.2.2 of ASCE 24.
    3. For dry floodproofed nonresidential buildings, construction documents shall include a statement that the dry floodproofing is designed in accordance with ASCE 24.
  2. For construction in flood hazard areas subject to high-velocity wave action:
    1. The elevation of the bottom of the lowest horizontal structural member as required by the lowest floor elevation inspection in Section 110.3.3.
    2. Construction documents shall include a statement that the building is designed in accordance with ASCE 24, including that the pile or column foundation and building or structure to be 111 attached thereto is designed to be anchored to resist flotation, collapse and lateral movement due to the effects of wind and flood loads acting simultaneously on all building components, and other load requirements of Chapter 16A.
    3. For breakaway walls designed to resist a nominal load of less than 10 psf (0.48 kN/m2) or more than 20 psf (0.96 kN/m2), construction documents shall include a statement that the breakaway wall is designed in accordance with ASCE 24.

SECTION 1613A
EARTHQUAKE LOADS

1613A.1 Scope. Every structure, and portion thereof, including nonstructural components that are permanently attached to structures and their supports and attachments, shall be designed and constructed to resist the effects of earthquake motions in accordance with ASCE 7 with all the modifications incorporated herein, excluding Chapter 14 and Appendix 11A. The seismic design category for a structure shall be determined in accordance with Section 1613A.

Exception: Structures that require special consideration oftheir response characteristics and environment that are not addressed by this code or ASCE 7 and for which other regulations provide seismic criteria, such as vehicular bridges, electrical transmission towers, hydraulic structures, buried utility lines and their appurtenances and nuclear reactors.

1613A.2 Definitions. The following words and terms shall, for the purposes of this section, have the meanings shown herein. Definition provided in Section 3402A.1 and ASCE 7 Section 11.2 shall apply when appropriate in addition to terms defined in this section.

ACTIVE EARTHQUAKE FAULT. A fault that has been the source of earthquakes or is recognized as a potential source of earthquakes, including those that have exhibited surface displacementwithin Holocene time (about 11,000 years) as determined by California Geological Survey (CGS) under the Alquist-Priolo Earthquake Fault Zoning Act, those included astype A or type B faults for the U.S. Geological Survey (USGS) National Seismic Hazard Maps, and faults considered to have been active in Holocene time be an authoritative source, federal,state or local governmental agency.

BASE. The level at which the horizontal seismic ground motions are considered to be imparted to the structure or the level at which the structure as a dynamic vibrator is supported. This level does not necessarily coincide with the ground level.

DESIGN EARTHQUAKE GROUND MOTION. The earth-quake ground motion that buildings and structures are specifically proportioned to resist in Section 1613A.

DISTANCE FROM AN ACTIVE EARTHQUAKE FAULT. Distance measured from the nearest point of the building to the closest edge of an Alquist-Priolo Earthquake Fault Zone for an active fault, if such a map exists, or to the closest mapped splay of the fault.

HOSPITAL BUILDINGS. Hospital buildings and all other medical facilities as defined in Section 1250, Health and Safety Code.

IRREGULAR STRUCTURE. A structure designed as having one or more plan or vertical irregularities per ASCE 7 Section 12.3.

MAXIMUM CONSIDERED EARTHQUAKE GROUND MOTION. The most severe earthquake effects considered by this code.

MECHANICAL SYSTEMS. For the purposes of determining seismic loads in ASCE 7, mechanical systems shall include plumbing systems as specified therein.

NEXT GENERATION ATTENUATION (NGA). Attenuation relations used for the 2008 United States Geological Survey (USGS) seismic hazards maps (for the Western United States) or their equivalent as determined by the enforcement agency.

ORTHOGONAL. To be in two horizontal directions, at 90 degrees (1.57 rad) to each other.

SEISMIC DESIGN CATEGORY. A classification assigned to a structure based on its occupancy category and the severity of the design earthquake ground motion at the site.

SEISMIC-FORCE-RESISTING SYSTEM. That part of the structural system that has been considered in the design to provide the required resistance to the prescribed seismic forces.

SITE CLASS. A classification assigned to a site based on the types of soils present and their engineering properties as defined in Section 1613A.5.2.

SITE COEFFICIENTS. The values of Fa and Fv indicated in Tables 1613A.5.3(1) and 1613A.5.3(2), respectively.

STRUCTURAL ELEMENTS. Floor or roof diaphragms, decking, joists, slabs, beams or girders, columns, bearing walls, retaining walls, masonry or concrete nonbearing walls exceeding one story in height, foundations, shear walls or other lateral-force-resisting members and any other elements necessary to the vertical and lateral strength or stability of either the building as a whole or any of its parts, including connection between such elements.

1613A.3 Existing buildings. [OSHPD 1 & 4]Additions, alterations, repairs or change of occupancy of existing buildings shall be in accordance with Chapter 34A.

1613A.4 Special inspections. Where required by Sections 1705A.3 through 1705A3.5, the statement of special inspections shall include the special inspections required by Section 1705A.3.6.

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1613A.5 Seismic ground motion values. Seismic ground motion values shall be determined in accordance with this section.

1613A.5.1 Mapped acceleration parameters. The parameters Ss and S1 shall be determined from the 0.2 and 1-second spectral response accelerations shown on Figures 1613.5(1) through 1613.5(14).

1613A.5.2 Site class definitions. Based on the site soil properties, the site shall be classified as either Site Class A, B, C, D, E or F in accordance with Table 1613A.5.2. When the soil properties are not known in sufficient detail to determine the site class, Site Class D shall be used unless the building official or geotechnical data determines that Site Class E or F soil is likely to be present at the site.

1613A..5.3 Site coefficients and adjusted maximum considered earthquake spectral response acceleration parameters. The maximum considered earthquake spectral response acceleration for short periods, SMS, and at 1-second period, SM1, adjusted for site class effects shall be determined by Equations 16A-36 and 16A-37, respectively:

Image

Image

where:

Sa = Site coefficient defined in Table 1613A.5.3(1).

Fv = Site coefficient defined in Table 1613A.5.3.(2).

S1 = The mapped spectral accelerations for short periods as determined in Section 1613A.5.1.

S1 = The mapped spectral accelerations for a 1-second period as determined in Section 1613A.5.1.

1613A.5.4 Design spectral response acceleration parameters. Five-percent damped design spectral response acceleration at short periods, SDS, and at 1-second period, SD1, shall be determined from Equations 16A-38 and 16A-39, respectively:

Image

Image

where:

SMS = The maximum considered earthquake spectral response accelerations for short period as determined in Section 1613A.5.3.

SM1 = The maximum considered earthquake spectral response accelerations for 1-second period as determined in Section 1613A.5.3.

TABLE 1613A.5.2
SITE CLASS DEFINITIONS
SITE
CLASS		SOIL PROFILE
NAME		AVERAGE PROPERTIES IN TOP 100 feet, SEE SECTION 1613.A.5.5
Soil shear wave velocity, vs, (ft/s)Standard penetration resistance,
N		Soil undrained shear strength, su, (psf)
AHard rockvs>5,000N/AN/A
BRock2,500<vs≤5,000N/AN/A
CVery dense soil and soft rock1,200<vs2,500N>50su2,000
DStiff soil profile600≤vs1,20015≤N≤501,000≤su≤2,000
ESoft soil profilevs<600N<15su<1,000
E—Any profile with more than 10 feet of soil having the following characteristics:
  1. Plasticity index PI>20,
  2. Moisture content w≥40%, and
  3. Undrained shear strength su<500 psf
F—Any profile containing soils having one or more of the following characteristics:
  1. Soils vulnerable to potential failure or collapse under seismic loading such as liquefiable soils, quick and highly sensitive clays, collapsible weakly cemented soils.
  2. Peats and/or highly organic clays(H<10 feet of peat and/or highly organic clay where H=thickness of soil)
  3. Very high plasticity clays (H>25 feet with plasticity index PI>75)
  4. Very thick soft/medium stuff clays(H>120 feet)
For SI: 1 foot=304.8 mm, 1 square foot=0.0929m2, 1 pound per square foot=0.0479kpa. N/A=Not applicable
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TABLE 1613A.5.3(1)
VALUES OF SITE COEFFICIENT Faa
SITECLASSMAPPED SPECTRAL RESPONSE ACCELERATION AT SHORT PERIOD
Ss≤0.25S8=0.50S8=0.75Ss=1.00Ss≥1.25
a. Use straight-line interpolation for intermediate values of mapped spectral response acceleration at short period, Ss
b. Values shall be determined in accordance with Section 11.4.7 of ASCE 7.
A0.80.80.80.80.8
B1.01.01.01.01.0
C1.21.21.11.01.0
D1.61.41.21.11.0
E2.51.71.20.90.9
FNote bNote bNote bNote bNote b
TABLE 1613A.5.3(1)
VALUES OF SITE COEFFICIENT Faa
SITECLASSMAPPED SPECTRAL RESPONSE ACCELERATION AT SHORT PERIOD
Ss≤0.25S8=0.50S8=0.75Ss=1.00Ss≥1.25
a. Use straight-line interpolation for intermediate values of mapped spectral response acceleration at 1-second period, S1
b. Values shall be determined in accordance with Section 11.4.7 of ASCE 7.
A0.80.80.80.80.8
B1.01.01.01.01.0
C1.71.61.51.41.3
D2.42.01.81.61.5
E3.53.22.82.42.4
FNote bNote bNote bNote bNote b

1613A.5.5 Site classification for seismic design. Site classification for Site Class C, D or E shall be determined from Table 1613A.5.5.

The notations presented below apply to the upper 100 feet (30 480 mm) of the site profile. Profiles containing distinctly different soil and/or rock layers shall be subdivided into those layers designated by a number that ranges from 1 to n at the bottom where there is a total of n distinct layers in the upper 100 feet (30 480 mm). The symbol i then refers to any one of the layers between 1 and n.

where:

vsi = The shear wave velocity in feet per second (m/s).

di = The thickness of any layer between 0 and 100 feet (30 480 mm).

where:

Image

Image

N1 is the Standard Penetration Resistance (ASTM D 1586) not to exceed 100 blows/foot (328 blows/m) as directly measured in the field without corrections. When refusal is met for a rock layer, N1 shall be taken as 100 blows/foot (328 blows/m).

Image

where N1 and d1 in Equation 16A-41 are cohesions soil, cohesive soil and rock layers.

Image

where:

Image

Use di and N1 for cohesionless soil layers only in Equation 16A-42.

ds = The total thickness of cohesionless soil layers in the top 100 feet (30 480 mm).

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m = The number of cohesionless soil layers in the top 100 feet (30 480 mm).

sui =The undrained shear strength in psf (kPa), not to exceed 5,000 psf (240 kPa), ASTM D 2166 or D 2850.

Image

where:

Image

dc = The total thickness of cohesive soil layers in the top 100 feet (30 480 mm).

k = The number of cohesive soil layers in the top 100 feet (30 480 mm).

PI = The plasticity index, ASTM D 4318.

w = The moisture content in percent, ASTM D 2216.

Where a site does not qualify under the criteria for Site Class F and there is a total thickness of soft clay greater than 10 feet (3048 mm) where a soft clay layer is defined by:su< 500 psf (24 kPa), w≥ 40 percent, and PI> 20, it shall be classified as Site Class E.

The shear wave velocity for rock, Site Class B, shall be either measured on site or estimated by a geotechnical engineer or engineering geologist/seismologist for competent rock with moderate fracturing and weathering. Softer and more highly fractured and weathered rock shall either be measured on site for shear wave velocity or classified as Site Class C.

The hard rock category, Site Class A, shall be supported by shear wave velocity measurements either on site or on profiles of the same rock type in the same formation with an equal or greater degree of weathering and fracturing. Where hard rock conditions are known to be continuous to a depth of 100 feet (30 480 mm), surficial shear wave velocity measurements are permitted to be extrapolated to assess vs.

The rock categories, Site Classes A and B, shall not be used if there is more than 10 feet (3048 mm) of soil between the rock surface and the bottom of the spread footing or mat foundation.

TABLE 1613A.5.5
SITE CLASSIFICATIONa
SITE CLASSvsN or NaftSu
For SI:1 foot per second = 304.8 mm per second, 1 pound per square foot = 0.0479 kN/m²
a. If the sh method is used and the Nucriteria differ, select the category with the softer soils (for example, use Site Class E instead of D).
E<600 ft/s< 15<1,000 psf
D600 to 1,200 ft/s15 to 501,000 to 2,000 psf
C1,200 to 2,500 ft/s>50>2,000

1613A.5.5.1 Steps for classifying a site.

  1. Check for the four categories of Site Class F requiring site-specific evaluation. If the site corresponds to any of these categories, classify the site as Site Class F and conduct a site-specific evaluation.
  2. Check for the existence of a total thickness of soft clay < 10 feet (3048 mm) where a soft clay layer is defined by: su < 500 psf (24 kPa), w ≥ 40 percent and PI > 20. If these criteria are satisfied, classify the site as Site Class E.
  3. Categorize the site using one of the following three methods with v
    1. vs for the top 100 feet (30 480 mm) (vs method).
    2. Nch for cohesionless soil layers (PI < 20) in the top 100 feet (30 480 mm) and average,su for cohesive soil layers (PI > 20) in the top 100 feet (30 480 mm) (Su method).
    3. Nel! for cohesionless soil layers (PI < 20) in the top 100 feet (30 480 mm) and average, Su for cohesive soil layers (PI> 20) in the top 100 feet (30 480 mm) (su method).

1613A.5.6 Determination of seismic design category. Structures classified as Occupancy Category I, II or III that are located where the mapped spectral response acceleration parameter at 1-second period, S1, is greater than or equal to 0.75 shall be assigned to Seismic Design Category E. Structures classified as Occupancy Category IV that are located where the mapped spectral response acceleration parameter at 1-second period, S1, is greater than or equal to 0.75 shall be assigned to Seismic Design Category F. All other structures shall be assigned to a seismic design Category D.

1613A5.6.1 Alternative seismic design category determination. Not permitted by DSA-SS & OSHPD.

1613A.5.6.2 Simplified design procedure. Not permitted by DSA-SS & OSHPD.

1613A.6 Alternatives to ASCE 7. The provisions of Section 1613A..6 shall be permitted as alternatives to the relevant provisions of ASCE 7

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1613A.6.1 Assumption of flexible diaphragm. Add the following text at the end of Section 12.3.1.1 of ASCE 7.

Diaphragms constructed of wood structural panels or untopped steel decking shall also be permitted to be idealized as flexible, provided all of the following conditions are met:

  1. Toppings of concrete or similar materials are not placed over wood structural panel diaphragms except for nonstructural toppings no greater than 1½ inches (38 mm) thick.
  2. Each line of vertical elements of the seismic-force-resisting system complies with the allowable story drift of Table 12.12-1.
  3. Vertical elements of the seismic-force-resisting system are light-frame walls sheathed with wood structural panels rated for shear resistance or steel sheets.
  4. Portions of wood structural panel diaphragms that cantilever beyond the vertical elements of the lateral-force-resisting system are designed in accordance with Section 4.2.5.2 of AF&PA SDPWS.

1613A.6.2 Additional seismic-force-resisting systems for seismically isolated structures. Add the following exception to the end of Section 17.5.4.2 of ASCE 7:

Exception: For isolated structures designed in accordance with this standard, the Structural System Limitations and the Building Height Limitations in Table 12.2-1 for ordinary steel concentrically braced frames (OCBFs) as defined in Chapter 11 and intermediate moment frames (IMFs) as defined in Chapter 11 are permittedto be taken as 160 feet (48 768 mm) for structures assigned to Seismic Design Category D,E or F, provided that the following conditions are satisfied;

  1. The value of R1as defined in Chapter 17 is taken as 1.
  2. For OCBFs, design is in accordance with AISC 341.
  3. For IMFs, design is in accordance with AISC 341. In addition, requirements of Section 9.3 of AISC 341 shall be satisfied.

1613A.6.3 Automatic sprinkler systems. Automatic sprinkler systems designed and installed in accordance with NFPA 13 shall be deemed to meet the requirements of Section 13.6.8 of ASCE 7.

Exception: The allowable values for design of anchors, hangers and bracings shall be determined in accordance with material chapters of this code in lieu of those in NFPA 13.

1613A.6.4 Autoclaved aerated concrete (AAC) masonry. Not permitted by DSA-SS & OSHPD.

1613A.6.5 Seismic controls for elevators. Seismic switches in accordance with Section 8.4.10 of ASME A17.1 shall be deemed to comply with Section 13.6.10.3 of ASCE 7.

1613A.6.6 Steel plate shear wall height limits. Modify Section 12.2.5.4 of ASCE 7 to read as follows:

12.2.5.4 Increased building height limit for steel braced frames, special steel plate shear walls and special reinforced concrete shear walls. The height limits in Table 12.2-1 are permitted to be increased from 160 feet (48 768 mm) to 240 feet (75 152 mm) for structures assigned to Seismic Design Category D or E and from 100 feet (30 480 mm) to 160 feet (48 768 mm) for structures assigned to Seismic Design Category F that have steel-braced frames, special steel plate shear walls or special reinforced concrete cast-in-place shear walls and that meet both of the following requirements:

  1. The structure shall not have an extreme torsional irregularity as defined in Table 12.2-1 (horizontal structural irregularity as defined in Table 12.2-1(horizontal structural irregularity Type 1b).
  2. The braced frames or shear walls in any one plane shall resist no more than 60 percent of the total seismic forces in each direction, neglecting accidental torsional effects.

1613A.6.7 Minimum distance for building separation. All buildings and structures shall be separated from adjoining structures. Separations shall allow for the maximum inelastic response displacement (σ)M.(σ)M shall be determined at critical locations with consideration for both translational and torsional displacements of the structure using Equation 16A-44 for DSA-SS and 16A-44B for OSHPD.

Image

Image

where:

Cd=Deflection amplification factor Table 12.2-1 of ASCE 7.

σmax=Maximum displacement defined in Section 12.8.4.3 of ASCE 7.

I=Importance factor in accordance with Section 11.5.1 of ASCE 7.

Adjacent buildings on the same property shall be separated by a distance not less than σMT, determined by Equation 16A-45.

Image

where:

σM1,,σM2=The maximum inelastic response displacements of the adjacent buildings in accordance with Equations 16A-44A or 16A-44B for OSHPD.

Where a structure adjoins a property line not common to a public way, the structure shall also be set back from the property line by not less than the maximum inelastic response displacement, σM,of that structure.

Exception: Smaller separations or property line set backs shall be permitted when justified by rational analyses.

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SECTION 1614A
STRUCTURAL INTEGRITY

1614A.1 General. Buildings classified as high-rise buildings in accordance with Section 403 and assigned to Occupancy Category III or IV shall comply with the requirements of this section. Frame structures shall comply with the requirements of Section 1614A.3. Bearing wall structures shall comply with the requirements of Section 1614A.4.

1614A.2 Definitions. The following words and terms shall, for the purposes of Section 1614A, have the meanings shown herein.

BEARING WALL STRUCTURE. A building or other structure in which vertical loads from floors and roofs are primarily supported by walls.

FRAME STRUCTURE. A building or other structure in which vertical loads from floors and roofs are primarily supported by columns.

1614A.3 Frame structures. Frame structures shall comply with the requirements of this section.

1614A.3.1 Concrete frame structures. Frame structures constructed primarily of the reinforced or prestressed concrete, either cast-in-place or precast, or a combination of these, shall conform to the requirements of ACI 318 Sections 7.13, 13.3.8.5, 13.3.8.6, 16.5, 18.12.6, 18.12.7 and 18.12.8 as applicable. Where ACI 318 requires that nonprestressed reinforcing or prestressing steel pass through the region bounded by the longitudinal column reinforcement, that reinforcing or prestressing steel shall have a minimum nominal tensile strength equal to two-third of the required one-way vertical strength of the connection of the floor or roof system to the column in each direction of beam or slab reinforcement passing through the column.

Exception: Where concrete slabs with continuous reinforcing having an area not less than 0.0015 times the concrete area in each of two orthogonal directions are present and are either monolithic with or equivalently bonded to beams, girders or columns, the longitudinal reinforcing or prestressing steel passing through the column reinforcement shall have a nominal tensile strength of one-third of the required one-way vertical strength of the connection of the floor or roof system to the column in each direction of beam or slab reinforcement passing through the column.

1614A.3.2 Structural steel, open web steel joist or joist girder, or composite steel and concrete frame structures. Frame structures constructed with a structural steel frame or a frame composed of open web steel joists, joist girders with or without other structural steel elements or a frame composed of composite steel or composite steel joists and reinforced concrete elements shall conform to the requirements of this section.

1614A.3.2.1 Columns. Each column splice shall have the minimum design strength in tension to transfer the design dead and live load tributary to the column between the splice and the splice or base immediately below.

1614A.3.2.2 Beams. End connections of all beams and girders shall have a minimum nominal axial tensile strength equal to the required vertical shear strength for allowable stress design(ASD) or two-thirds of the required shear strength for load and resistance factor design(LRFD) but not less than 10 kips (45 kN). For the purpose of this section, the shear force and the axial tensile force need not be considered to act simultaneously.

Exception: Where beams, girders, open web joist and joist girders support a concrete slab or concrete slab on metal deck that is attached to the beam or girder with not less than 3/8-inch-diameter(9.5 mm) headed shear studs, at a spacing of not more than 12 inches (305 mm) on center, averaged over the length of the member, or other attachment having equivalent shear strength, and the slab contains continuous distributed reinforcement in each of two orthogonal directions with an area not less than 0.0015 times the concrete area, the nominal axial tension strength of the end connection shall be permitted to be taken as half the required vertical shear strength for ASD or one-third of the required shear strength for LRFD, but not less than 10 kips (45 kN).

1614A.4 Bearing wall structures. Bearing wall structures shall have vertical ties in all load-bearing walls and longitudinal ties, transverse ties and perimeter ties at each floor level in accordance with this section and as shown in Figure 1614A.4.

1614A.4.1 Concrete wall structures. Precast bearing wall structures constructed solely of reinforced or prestressed concrete, or combinations of these shall conform to the requirements of Sections 7.13, 13.3.8.5 and 16.5 of ACI 318.

1614A.4.2 Other bearing wall structures. Ties in bearing wall structures other than those covered in Section 1614A.4.1 shall conform to this section.

1614A.4.2.1 Longitudinal ties. Longitudinal ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls. or connections of continuous framing members to walls. Longitudinal ties shall extend across interior load-bearing walls and shall connect to exterior load-bearing walls and shall be spaced at not greater than 10 feet (3038 mm) on center. Ties shall have a minimum nominal tensile strength, TT, given by Equation 16A-46. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

Equation 16A-46

where:

L = The span of the horizontal element in the direction of the tie, between bearing walls, feet (m).

w = The weight per unit area of the floor or roof in the span being tied to or across the wall, psf (N/m2).

S = The spacing between ties, feet (m).

117

αT=A coefficient with a value of 1,500 pounds per foot (2.25 kN/m) for masonry bearing wall structures and a value of 375 pounds per foot (0.6 kN/m) for structures with bearing walls of cold-formed steel light-frame construction.

1614A.4.2.2 Transverse ties. Transverse ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Transverse ties shall be placed no farther apart than the spacing of load-bearing walls. Transverse ties shall have minimum nominal tensile strength TT, given by Equation 16A-46. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

1614A.4.2.3 Perimeter ties. Perimeter ties shall consist of continuous reinforcement in slabs; continuous or spliced decks or sheathing; continuous or spliced members framing to, within or across walls; or connections of continuous framing members to walls. Ties around the perimeter of each floor and roof shall be located within 4 feet (1219 mm) of the edge and shall provide a nominal strength in tension not less than Tp given by Equation 16A-47. For ASD the minimum nominal tensile strength shall be permitted to be taken as 1.5 times the allowable tensile stress times the area of the tie.

T=Transverse L=Longitudinal V=Vertical P=Perimeter

Equation 16A-47

For SI:

Tp = 90.7w βr

where:

w = As defined in Section 1614A.4.2.1.

βT= A coefficient with a value of 16,000 pounds (7200 kN) for structures with masonry bearing walls and a value of 4,000 pounds (1300 kN) for structures with bearing walls of cold-formed steel light-frame construction.

1614A.4.2.4 Vertical ties. Vertical ties shall consist of continuous or spliced reinforcing, continuous or spliced members, wall sheathing or other engineered systems. Vertical tension ties shall be provided in bearing walls and shall be continuous over the height of the building. The minimum nominal tensile strength for vertical ties within a bearing wall shall be equal to the weight of the wall story plus the weight of the diaphragm tributary to the wall in the story below. No fewer than two ties shall be provided for each wall. The strength of each tie need not exceed 3,000 pounds per foot (450 kN/m) of wall tributary to the tie for walls of masonry construction or 750 pounds per foot (140 kN/m) of wall tributary to the tie for walls of cold-formed steel light-frame construction.

FIGURE 1614A.4 LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES

FIGURE 1614A.4
LONGITUDINAL, PERIMETER, TRANSVERSE AND VERTICAL TIES

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SECTION 1615A
MODIFICATIONS TO ASCE 7

1615A.1 General. The text of ASCE 7 shall be modified as indicated in Sections 1615A.1.1 through 1615A.1.38.

1615A.1.1 ASCE 7, Section 11.1. Modify ASCE 7 Section 11.1 by the adding Section 11.1.5 as follows:

11.1.5 Structural design criteria. Where design reviews are required in ASCE 7, Chapters 16, 17 or 18, the ground motion, analysis, and design methods, material assumptions and acceptance criteria proposed by the engineer shall be submitted to the enforcement agency in the form of structural design criteria for approval.

[OSHPD 1 & 4] Peer review requirements in Section 3414A shall apply to design reviews required by ASCE 7 Chapters 17 and 18.

1615A.1.2 A [DSA-SS] ASCE 7, Section 11.4.7. Modify ASCE 7 Section 11.4.7 as follows:

11.4.7 Site-specific ground motion procedures. The site-specific ground motion procedure set forth in ASCE 7 Section 21 as modified in Section 1803A.6 of this code is permitted to be used to determine ground motion for any structure.

Unless otherwise approved, the site-specific procedure per ASCE 7 Section 21 as modified by Section 1803A.6 of this code shall be used where any of the following conditions apply:

  1. A site response analysis shall be performed per Section 21.1, and a ground motion hazard analysis shall be performed in accordance with Section 21.2 for the following structures:
    1. Structure located in Type E soils and mapped MCE spectral acceleration at short periods (Ss) exceeds 2.0g.
    2. Structures located in Type F soils.

      Exceptions:

      1. Where Ss is less than 0.20g, use of Type E soil profile shall be permitted.
      2. Where exception to Section 20.3.1 is applicable except for base isolated buildings.
  2. A ground motion hazard analysis shall be performed in accordance with Section 21.2 when:
    1. A time history response analysis of the building is performed as part of the design.
    2. The building site is located in an area identified in Section 4-317(e) of the California Administrative Code (Part 1, Title 24, C.C.R).
    3. seismically isolated structures and for structures with damping systems.

1615A.1.2B. [OSHPD 1 & 4] Modify ASCE 7 Section 11.4.7 by adding the following:

For buildings assigned to Seismic Design Category F, or when required by the building official, a ground motion hazard analysis shall be performed in accordance with ASCE 7 Chapter 21 as modified by Section 1803A.6.

1615A.1.3 ASCE 7, Table 12.2-1. Modify ASCE 7 Table 12.2-1 as follows:

  1. BEARING WALL SYSTEMS

    5. Intermediate Precast Shear Walls-Not permitted by OSHPD.

    14. Light-framed walls with shear panels of all other materials— Not permitted by OSHPD and DSA-SS.

  2. BUILDING FRAME SYSTEMS

    2. Steel eccentrically braced frames, nonmoment-resisting connections at columns away from links-—Not permitted by OSHPD.

    4. Ordinary steel concentrically braced frames —Not permitted by OSHPD.

    9. Intermediate Precast Shear Walls—Not permitted by OSHPD.

    24. Light-framed walls with shear panels of all other materials—Not permitted by OSHPD and DSA-SS.

    25. Buckling-restrained braced frames, non-moment-resisting beam-column connections—Not permitted by OSHPD.

    27. Special steel plate shear wall—Not permitted by OSHPD.

  3. MOMENT-RESISTING FRAME SYSTEMS

    2. Special steel truss moment frames—Not permitted by OSHPD.

    3. Intermediate steel moment frames—Not permitted by OSHPD.

    4. Ordinary steel moment frames—Not permitted by OSHPD.

Exceptions:

  1. Systems listed in this section can be used as an alternative system when preapproved by the enforcement agency.
  2. Rooftop or other supported structures not exceeding two stories in height and 10 percent of the total structure weight can use the systems in this section when designed as components per ASCE 7 Chapter 13. 119
  3. Systems listed in this section can be used for seismically isolated buildings when permitted by Section 1613A.6.2.

1615A.1.4 ASCE 7, Section 12.2.3.1. Modify ASCE 7 Section 12.2.3.1 by adding the following additional requirements for a two stage equivalent lateral force procedure or modal response spectrum procedure:

e. Where design of element of the upper portion is governed by special seismic load combinations, the special loads shall be considered in the design of the lower portion.

1615A.1.5 ASCE 7, Section 12.3.3. Modify first sentence of ASCE 7 Section 12.3.3.1 as follows:

12.3.3.1 Prohibited horizontal and vertical irregularities for Seismic Design Categories D through F. Structures assigned to Seismic Design Category D, E or F having horizontal structural irregularities Type 1b of Table 12.3-1 or vertical structural irregularities Type 1b, 5a or 5b of Table 12.3-2 shall not be permitted.

1615A.1.6 ASCE 7, Section 12.7.2. Modify ASCE 7 Section 12.7.2 by adding Item 5 to read as follows:

5. Where buildings provide lateral support for walls retaining earth, and the exterior grades on opposite sides of the building differ by more than 6 feet (1829 mm), the load combination of the seismic increment of earth pressure due to earthquake acting on the higher side, as determined by a geotechnical engineer qualified in soils engineering plus the difference in earth pressures shall be added to the lateral forces provided in this section.

1615A.1.7 ASCE 7, Section 12.8.7. Modify ASCE 7 Section 12.8.7 by replacing Equation 12.8-16 as follows:

(12.8-16)

1615A.1.8 ASCE 7, Section 12.9.4 Replace ASCE 7 Section 12.9.4 as follows:

12.9.4 Scaling design values of combined response. Modal base shear shall not be less than the base shear calculated using the equivalent lateral force procedure of Section 12.8.

1615A.1.9 ASCE 7, Section 12.10.2.1. Modify ASCE 7 Section 12.10.2.1 by adding the following:

The value of Ω0ΩE used in load combinations with over strength factors in ASCE 7-05 Section 12.4.3.2 for design of collector elements, splices and their connections to resisting elements may be taken as the largest of the following:

  1. Ω0Fx(where Fx is given by ASCE 7-05 Eq.12.8-11)
  2. Ω0Fpx(where Fpxis given by ASCE 7-05 Eq. 12.10-1 ignoring the 0.2SDSIwpxminimum)
  3. 0.2SDSIwpx(Minimum value from Section 12.10.1.1)

1615A.1.10 ASCE 7, Section 12.13.1. Modify ASCE 7 Section 12.13.1 by adding Section 12.13.1.1 as follows:

12.13.1.1 Foundations and superstructure-to-foundation connections. The foundation shall be capable of transmitting the design base shear and the overturning forces from the structure into the supporting soil. Stability against overturning and sliding shall be in accordance with Section 1605A.1.1.

In addition, the foundation and the connection of the superstructure elements to the foundation shall have the strength to resist, in addition to gravity loads, the lesser of the following seismic loads:

  1. The strength of the superstructure elements.
  2. The maximum forces that would occur in the fully yielded structural system.
  3. Forces from the Load Combinations with over strength factor in accordance with ASCE 7 Section 12.4.3.2.

Exceptions:

  1. Where referenced standards specify the use of higher design loads.
  2. When it can be demonstrated that inelastic deformation of the foundation and superstructure-to-foundation connection will not result in a weak story or cause collapse of the structure.
  3. Where basic structural system consists of light framed walls with shear panels.

Where the computation of the seismic over turning moment is by the equivalent lateral-force method or the modal analysis method, reduction in overturning moment permitted by section 12.13.4 of ASCE 7 may be used.

Where moment resistance is assumed at the base of the superstructure elements, the rotation and flexural deformation of the foundation as well as deformation of the superstructure-to-foundation connection shall be considered in the drift and deformation compatibility analyses.

1615A.1.11 ASCE 7, Section 13.1.3. [OSHPD 1 & 4] Modify ASCE 7 Section 13.1.3 by the following:

For position retention, the design of supports and attachments for all nonstructural components shall have a component importance factor, Ip, equal to 1.5.

1615A.1.12 ASCE 7, Section 13.1.4. Replace ASCE 7 Section 13.1.4 with the following:

13.1.4 Exceptions. The following nonstructural components are exempt from the requirements of this section:

  1. Furniture (except storage cabinets as noted in Table 13.5-1).
  2. Temporary or moveable equipment.

    Exceptions:

    1. Equipment shall be anchored if it is permanently attached to the building utility services such as electricity, gas or water.120 For the purposes of this requirement, “permanently attached” shall include all electrical connections except three-prong plugs for duplex receptacles.
    2. The enforcement agency shall be permitted to require temporary attachments for movable equipment which is usually stationed in one place and heavier than 400 pounds, when they are not in use for a period longer than 8 hours at a time.
    3. Architectural, mechanical and electrical components in Seismic Design Categories D, E or F where all of the following apply:
      1. The component is positively attached to the structure;
      2. Flexible connections are provided between the component and associated ductwork, piping and conduit; and either:
        1. The component weighs 400 pounds (1780 N) or less and has a center of mass located 4 feet (1.22 m) or less above the adjacent floor or roof level that directly support the component;

          Exception: Special Certification Requirements for Designated Seismic Systems in accordance with Section 13.2.2 shall apply.

          or

        2. The component weighs 20 pounds (89 N) or less or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.

          Exception: The enforcement agency shall be permitted to require attachments for equipment with hazardous contents to be shown on construction documents irrespective of weight.

1615A.1.13 ASCE 7, Section 13.3.2. Modify ASCE 7 Section 13.3.2 by adding the following:

The seismic relative displacements to be used in design of displacement sensitive nonstructural components is Dp I instead of Dp where Dp is given by Equation 13.3–5 to 13.3–8 and I is the building importance factor given in Section 11.5.

1615A.1.14 ASCE 7, Section 13.4 Replace ASCE 7 Sections 13.4.1 and 13.4.2 with the following:

13.4.1 Design force in the attachment. The force in the attachment shall be determined based on the prescribed forces and displacements for the component as determined in Sections 13.3.1 and 13.3.2 except that Rp shall not be taken as larger than 6.

13.4.2 Anchors in concrete or masonry.

13.4.2.1 Anchors in concrete. Anchors in concrete used for component anchorage shall be designed in accordance with Appendix D of ACI 318.

13.4.2.2 Anchors in masonry. Anchors in masonry used for component anchorage shall be designed in accordance with ACI 530. Anchors shall be designed to be governed by the tensile or shear strength of a ductile steel element.

Exception: Anchors shall be permitted to be designed so that the attachment that the anchor is connecting to the structure undergoes ductile yielding at a load level corresponding to anchor forces not greater than their design strength, or the minimum design strength of the anchors shall be at least 2.5 times the factored forces transmitted by the attachment.

13.4.2.3 Postinstalled anchors in concrete and masonry. Postinstalled anchors shall fulfill the requirements of Section 13.4.2.1 or 13.4.2.2. Postinstalled anchors in concrete used for component anchorage shall be pre-qualified for seismic applications in accordance with ACI 355.2, ICC-ES AC193 or ICC-ES AC308. Postinstalled anchors in masonry used for component anchorage shall be prequalified for seismic applications in accordance with ICC-ES AC01, AC58 or AC106.

Exceptions:

1) Adhesive anchors shall not be permitted in overhead applications or application with sustained (continuous) tension load that can lead to creep.

2) Anchors pre-qualified for seismic applications need not be governed by the steel strength of a ductile steel element.

1615A.1.15 ASCE 7, Section 13.4.5. Replace ASCE 7 Section 13.4.5 with the following:

13.4.5 Power actuated fasteners. Power actuated fasteners in concrete or steel shall not be used for sustained tension loads or for brace applications in Seismic Design Categories D, E, or F unless approved for seismic loading. Power actuated fasteners in masonry shall not be permitted unless approved for seismic loading.

Exception: Power actuated fasteners in concrete used for support of acoustical tile or lay-in panel suspended ceiling applications and distributed systems where the service load on any individual fastener does not exceed 90 lb (400 N). Power actuated fasteners in steel where the service load on any individual fastener does not exceed 250 lb (1,112 N).

1615A.1.16 ASCE 7, Section 13.5.6. Replace ASCE 7, Section 13.5.6 with the following:

13.5.6 Suspended ceilings. Suspended ceilings shall be in accordance with this section.

13.5.6.1 Seismic forces. The weight of the ceiling, Wp, shall include the ceiling grid; ceiling tiles or panels; light fixtures if attached to, clipped to, or laterally supported by the ceiling grid; and other components that are laterally supported by the ceiling. Wp shall be taken as not less than 4 psf (19 N/m2).

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The seismic force, Fp shall be transmitted through the ceiling attachments to the building structural elements or the ceiling-structure boundary.

13.5.6.2 Seismic design requirements. Suspended acoustical tile or lay-in panel ceilings shall be designed in accordance with ASTM E 580 Section 5.2.8.8 and the requirements of Sections 13.5.6.2.1 and 13.5.6.2.2, or be designed in accordance with Section 13.2.1.1, or be seismically qualified in accordance with Sections 13.2.5 or 13.2.6.

13.5.6.2.1 Industry standard construction for acoustical tile or lay-in panel ceilings. Acoustical tile or lay-in panel ceilings in Seismic Design Categories D, E, and F shall be designed and installed in accordance with ASTM C 635, ASTM C 636, and ASTM E 580, Section 5 - Seismic Design Categories D, E, and F as modified by Section 13.5.6.2.2.

13.5.6.2.2 Modification to ASTM E 580. Modify ASTM E 580 by the following:

  1. Exitways. Lay-in ceiling assemblies in exitways of hospitals and essential services buildings shall be installed with a main runner or cross runner surrounding all sides of each piece of title, board or panel and each light fixture or grille. A cross runner that supports another cross runner shall be considered as a main runner for the purpose of structural classification. Splices or intersections of such runners shall be attached with through connectors such as pop rivets, screws, pins, plates with end tabs or other approved connectors.
  2. Corridors and Lobbies. Expansion joints shall be provided in the ceiling at intersections of corridors and at junctions of corridors and lobbies or other similar areas.
  3. Lay-in panels. Metal panels and panels weighing more than ½ pounds per square foot (24 N/m2) other than acoustical tiles shall be positively attached to the ceiling suspension runners.
  4. Lateral force bracing. Lateral force bracing is required for all ceiling areas except that they shall be permitted to be omitted in rooms with floor areas up to 144 square feet when perimeter support in accordance with ASTM E 580 Sections 5.2.2 and 5.2.3 are provided and perimeter walls are designed to carry the ceiling lateral forces.
  5. Ceiling fixtures. Fixtures installed in acoustical tile or lay-in panel ceilings shall be mounted in a manner that will not compromise ceiling performance.
    All recessed or drop-in light fixtures and grilles shall be supported directly from the fixture housing to the structure above with a minimum of two 12 gage wires located at diagonally opposite corners. Leveling and positioning of fixtures may be provided by the ceiling grid. Fixture support wires may be slightly loose to allow the fixture to seat in the grid system. Fixtures shall not be supported from main runners or cross runners if the weight of the fixtures causes the total dead load to exceed the deflection capability of the ceiling suspension system.
    Fixtures shall not be installed so that the main runners or cross runners will be eccentrically loaded.
    Surface-mounted fixtures shall be attached to the main runner with at least two positive clamping devices made of material with a minimum of 14 gage. Rotational spring catches do not comply. A 12 gage suspension wire shall be attached to each clamping device and to the structure above.
  6. Partitions. Where the suspended ceiling system is required to provide lateral support for the permanent or relocatable partitions, the connection of the partition to the ceiling system, the ceiling system members and their connections, and the lateral force bracing shall be designed to support the reaction force of the partition from prescribed loads applied perpendicular to the face of the partition. Partition connectors, the suspended ceiling system and the lateral-force bracing shall all be engineered to suit the individual partition application and shall be shown or defined in the drawings or specifications.

1615A.1.17 ASCE 7, Section 13.5.7. [OSHPD 1& 4] Modify ASCE 7 Section 13.5.7 by the following:

All access floors shall be special access floors in accordance with Section 13.5.7.2.

1615A.1.18 Reserved.

1615A.1.19 Reserved.

1615A.1.20 ASCE 7, Section 13.6.5. Modify ASCE 7, Section 13.6.5 by deleting Item 6 in Section 13.6.5.5 and adding Section 13.6.5.6 as follows:

13.6.5.6 Conduit, Cable Tray, and Other Electrical Distribution Systems (Raceways). Raceways shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Conduit greater than 2.5 inches (64 mm) trade size and attached to panels, cabinets or other equipment subject to seismic relative displacement of Section 13.3.2 shall be provided with flexible connections or designed for seismic forces

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and seismic relative displacements as required in Section 13.3.

Exceptions:

  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for raceways where either:
    1. Trapeze assemblies are used to support raceways and the total weight of the race way supported by trapeze assemblies is less than 10 lb/ft (146 N/m), or
    2. The raceway is supported by hangers and each hanger in the raceway run is 12 in. (305 mm) or less in length from the raceway support point to the supporting structure. Where rod hangers are used with a diameter greater than 3⁄8 inch, they shall be equipped with swivels to prevent inelastic bending in the rod.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for conduit, regardless of the value of Ip, where the conduit is less than 2.5 in. (64 mm) trade size.

1615A.1.21 ASCE 7, Section 13.6.7. Replace ASCE 7, Section 13.6.7 with the following:

13.6.7 Ductwork. HVAC and other ductwork shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Ductwork designed to carry toxic, highly toxic, or explosive gases, or used for smoke control shall be designed and braced without considering the Exceptions noted below.

Exceptions:

The following exceptions pertain to ductwork not designed to carry toxic, highly toxic, or flammable gases or used for smoke control:

  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for ductwork where either:
    1. the total weight of the ductwork supported by trapeze assemblies is less than 10 lb/ft (146 N/m); or
    2. The ductwork is supported by hangers and each hanger in the duct run is 12 in. (305 mm) or less in length from the duct support point to the supporting structure. Where rod hangers are used with a diameter greater than 3⁄8 inch, they shall be equipped with swivels to prevent inelastic bending in the rod.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required where provisions are made to avoid impact with larger ducts or mechanical components or to protect the ducts in the event of such impact; and HVAC ducts have a cross-sectional area of 6 ft2 (0.557 m2) or less, or weigh 10 lb/ft (146 N/m) or less.

HVAC duct systems fabricated and installed in accordance with standards approved by the authority having jurisdiction shall be deemed to meet the lateral bracing requirements of this section.

Components that are installed in-line with the duct system and have an operating weight greater than 75 lb (334 N), such as fans, heat exchangers and humidifiers, shall be supported and laterally braced independent of the duct system and such braces shall meet the force requirements of Section 13.3.1. Appurtenances such as dampers, louvers and diffusers shall be positively attached with mechanical fasteners. Unbraced piping attached to in-line equipment shall be provided with adequate flexibility to accommodate the seismic relative displacements of Section 13.3.2.

1615A.1.22 ASCE 7, Section 13.6.8. Replace ASCE 7, Section 13.6.8 with the following:

13.6.8 Piping Systems. Unless otherwise noted in this section, piping systems shall be designed for the seismic forces and seismic relative displacements of Section 13.3. ASME pressure piping systems shall satisfy the requirements of Section 13.6.8.1. Fire protection sprinkler piping shall satisfy the requirements of Section 13.6.8.2. Elevator system piping shall satisfy the requirements of Section 13.6.10.

Where other applicable material standards or recognized design bases are not used, piping design including consideration of service loads shall be based on the following allowable stresses:

  1. For piping constructed with ductile materials (e.g., steel, aluminum, or copper), 90 percent of the minimum specified yield strength.
  2. For threaded connections in piping constructed with ductile materials, 70 percent of the minimum specified yield strength.
  3. For piping constructed with nonductile materials (e.g., cast iron, or ceramics), 10 percent of the material minimum specified tensile strength.
  4. For threaded connections in piping constructed with nonductile materials, 8 percent of the material minimum specified tensile strength.

Piping not detailed to accommodate the seismic relative displacements at connections to other components shall be provided with connections having sufficient flexibility to avoid failure of the connection between the components.

13.6.8.1 ASME Pressure Piping Systems. Pressure piping systems, including their supports, designed and constructed in accordance with ASME B 31 shall be deemed to meet the force, displacement, and other requirements of this section. In lieu of specific force and displacement requirements provided in ASME B

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31, the force and displacement requirements of Sections 13.3 shall be used.

13.6.8.2 Fire protection sprinkler piping systems. Fire protection sprinkler piping designed and constructed in accordance with NFPA 13 shall be deemed to meet the force and displacement requirements of this section. The exceptions of Section 13.6.8.3 shall not apply.

Exception: Pipe hangers, bracing, and anchor capacities shall be determined in accordance with material chapters of the California Building Code, in lieu of using those in NFPA 13. The force and displacement requirements of Section 13.3 or those in the NFPA 13 may be used for design.

13.6.8.3 Exceptions. Design of piping systems and attachments for the seismic forces and relative displacements of Section 13.3 shall not be required where one of the following conditions apply:

  1. Trapeze assemblies are used to support piping whereby no single pipe exceeds the limits set forth in 3a. or b. below and the total weight of the piping supported by the trapeze assemblies is less than 10 lb⁄ft (146 N/m).
  2. The piping is supported by hangers and each hanger in the piping run is 12 in. (305 mm) or less in length from the top of the pipe to the supporting structure. Where pipes are supported on a trapeze, the trapeze shall be supported by hangers having a length of 12 in. (305 mm) or less. Where rod hangers are used with a diameter greater than 3⁄8 inch, they shall be equipped with swivels, eye nuts or other devices to prevent bending in the rod.
  3. Piping having an Rpin Table 13.6– of 4.5 or greater is used and provisions are made to avoid impact with other structural or nonstructural components or to protect the piping in the event of such impact and where the following size requirements are satisfied:
    1. For Seismic Design Categories D, E or F and values of Ipgreater than one, the nominal pipe size shall be 1 inch (25 mm) or less.
    2. For Seismic Design Categories D, E or F, where Ip = 1.0 the nominal pipe size shall be 3 inches (80 mm) or less.

The exceptions above shall not apply to elevator piping.

13.6.8.4 Other Piping Systems. Piping not designed and constructed in accordance with ASME B 31 or NFPA 13 shall comply with the requirements of Section 13.6.11.

1615A.1.23 ASCE 7, Section 13.6.10.1. Modify ASCE 7 Section 13.6.10.1 by adding Section 13.6.10.1.1 as follows:

13.6.10.1.1 Elevators guide rail support. The design of guide rail support-bracket fastenings and the supporting structural framing shall use the weight of the counter-weight or maximum weight of the car plus not less than 40 percent of its rated load. The seismic forces shall be assumed to be distributed one third to the top guiding members and two thirds to the bottom guiding members of cars and counterweights, unless other substantiating data are provided. In addition to the requirements of ASCE 7 Section 13.6.10.1, the minimum seismic forces shall be 0.5g acting in any horizontal direction.

1615A.1.24 ASCE 7, Section 13.6.10.4. Replace ASCE 7 Section 13.6.10.4 as follows:

13.6.10.4 Retainer plates. Retainer plates are required at the top and bottom of the car and counterweight, except where safety devices acceptable to the enforcement agency are provided which meet all requirements of the retainer plates, including full engagement of the machined portion of the rail. The design of the car, cab stabilizers, counterweight guide rails and counterweight frames for seismic forces shall be based on the following requirements:

  1. The seismic force shall be computed per the requirements of ASCE 7 Section 13.6.10.1. The minimum horizontal acceleration shall be 0.5g for all buildings.
  2. Wp shall equal the weight of the counterweight or the maximum weight of the car plus not less than 40 percent of its rated load.
  3. With the car or counterweight located in the most adverse position, the stress in the rail shall not exceed the limitations specified in these regulations, nor shall the deflection of the rail relative to its supports exceed the deflection listed below:
    RAIL SIZE (weight per foot of length, pounds)WIDTH OF MACHINED SURFACE (inches)ALLOWABLE RAIL DEFLECTION (inches)
    For SI: 1 inch =25 mm, 1 foot =305 mm, 1 pound =0.454 kg.
    Note: Deflection limitations are given to maintain a consistent factor of safety against disengagement of retainer plates from the guide rails during an earthquake.
    81¼0.20
    111½0.30
    121¾0.40
    15131/320.50
    18½131/320.50
    22½20.50
    302¼0.50
  4. Where guide rails are continuous over supports and rail joints are within 2 feet (610 mm) of their supporting brackets, a simple span may be assumed.
  5. The use of spreader brackets is allowed.
  6. Cab stabilizers and counterweight frames shall be designed to withstand computed lateral load with a minimum horizontal acceleration of 0.5g.

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1615A.1.25 ASCE 7, Section 16.1.3.2. Modify ASCE 7 Section 16.1.3.2 by the following:

Where next generation attenuation relations are used in accordance with Section 1803A.6.2, each pair of motions shall be scaled such that in the period range from 0.2T to 1.5T, the average of the SRSS spectra from all horizontal component pairs does not fall below the corresponding ordinate of the design response spectrum determined using NGA relations.

At sites within 3.1 miles (5 km) of an active fault that controls the hazard, each pair of components shall be rotated to the fault-normal and fault-parallel direction of the causative fault, and shall be scaled so that average of the fault-normal components is not less than the Maximum Considered Earthquake (MCE) response spectrum determined using NGA relations for each period range from 0.2T to 1.5T.

1615A.1.26 ASCE 7, Section 16.1.4. Modify ASCE 7 Section 16.1.4 by the following:

For each ground motion analyzed, the individual response parameters shall be multiplied by the following scalar quantities:

  1. Force response parameters shall be multiplied by I/R, where I is the importance factor determined in accordance with Section 11.5.1, and R is the response modification coefficient selected in accordance with Section 12.2.1.
  2. Drift quantities shall be multiplied by Cd/R, where Cd is the deflection amplification factor specified in Table 12.2–1.

The distribution of horizontal shear shall be in accordance with Section 12.8.4.

1615A.1.27 ASCE 7, Section 16.2.4. Modify ASCE 7 Section 16.2.4 by the following:

a) Where site is located within 3.1 miles (5 km) of an active fault at least seven ground motions shall be analyzed and response parameters shall be based on larger of the average of the maximum response with ground motions applied as follows:

  1. Each of the ground motions shall have their maximum component at the fundamental period aligned in one direction.
  2. Each of the ground motion’s maximum component shall be rotated orthogonal to the previous analysis direction.

b) Where site is located more than 3.1 miles (5 km) from an active fault at least 10 ground motions shall be analyzed. The ground motions shall be applied such that one-half shall have their maximum component aligned in one direction and the other half aligned in the orthogonal direction. The average of the maximum response of all the analyses shall be used for design.

1615A.1.28 ASCE 7, Section 16.2.4.2 [OSHPD 1 & 4] Modify ASCE 7 Section 16.2.4.2 by the following:

Acceptance criteria for elements subjected to deformation beyond their linear range of response shall be based on ASCE 41 for Immediate Occupancy (10) at Design Earthquake (DE) and Life Safety (LS) at Maximum Considered Earthquake (MCE). For LS acceptance criteria at MCE, primary components shall be within the acceptance criteria for primary components and secondary components shall be within the acceptance criteria for secondary components.

1615A.1.29 ASCE 7, Section 17.2.1. Modify ASCE 7 Section 17.2.1 by adding the following:

The importance factor, Ipfor parts and portions of a seismically isolated building shall be the same as that required for a fixed-base building of the same occupancy category.

1615A.1.30 ASCE 7, Section 17.2.4.7. Modify ASCE 7 Section 17.2.4.7 by adding the following:

The effects of uplift and/or rocking shall be explicitly accounted for in the analysis and in the testing of the isolator units.

1615A.1.31 ASCE 7, Section 17.2.5.2. Modify ASCE 7, Section 17.2.5.2 by adding the following:

The separation requirements for the building above the isolation system and adjacent buildings shall be the sum of the factored displacements for each building. The factors to be used in determining separations shall be:

  1. For seismically isolated buildings, the deformation resulting from the analyses using the maximum considered earthquake unmodified by RI
  2. For fixed based buildings, Cd times the elastic deformations resulting from an equivalent static analysis using the seismic base shear computed via ASCE 7 Section 12.8.

1615A.1.32 ASCE 7, Section 17.3.2. Replace ASCE 7, Section 17.3.2 with the following:

17.3.2 Ground Motion Histories. Where response history procedures are used, ground motions shall consist of pairs of appropriate horizontal ground motion acceleration components developed in accordance with Section 16.1.3.2 except that 0.2T and 1.5T shall be replaced by 0.5 TD and 1.25TMrespectively, where TD and TM are defined in Section 17.5.3.

1615A.1.33 ASCE 7, Section 17.4. Modify ASCE 7, Section 17.4 by adding the following:

17.4.2.3 Linear procedures. Linear procedures shall be limited to structures located at sites with S1 less than 0.6g.

1615A.1.34 ASCE 7, Section 17.6 Modify ASCE 7, Section 17.6 by the following:

17.6.1.1 Minimum seismic force. For the response spectrum and linear response history procedures, Vb and Vs, shall not be taken less than those calculated in accordance with Equations 17.5– and 17.5–

1615A.1.35 ASCE 7, Section 18.3.1. Modify ASCE 7, Section 18.3.1 by replacing the third paragraph with the following:

If the calculated force in an element of the seismic force resisting system does not exceed 1.5 times its nominal

125

strength for the Maximum Considered Earthquake (MCE) nor its nominal strength for the design earthquake (DE), the element is permitted to be modeled as linear.

1615A.1.36 ASCE 7, Section 21.4. Replace ASCE 7, Section 21.4 with the following:

21.4 Design Acceleration Parameters. Where the site-specific procedure is used to determine the design ground motion in accordance with Section 21.3, the parameter SDSshall be taken as the spectral acceleration, Sw obtained from the site-specific spectra at a period of 0.2 sec, except that it shall not be taken less than 90 percent of the peak spectral acceleration, Sa, at any period larger than 0.2 second. The parameter SD1shall be taken as the greater of the spectral acceleration, Sw, at a period of 1 sec or two times the spectral acceleration, Sw at a period of 2 sec.

For use with the equivalent lateral force procedure, the site specific spectral acceleration, Saat T shall be permitted to replace SD1/T in Equation 12.8-3 and SD1TL/T2in Equation 12.8-4. The parameter SDScalculated per this section shall be permitted to be used in Equations 12.8-2 and 12.8-5. The mapped value of S1shall be used in Equation 12.8-6. The parameters SMSand SM1shall be taken as 1.5 times SDSand SD1, respectively. The values so obtained shall not be less than 80 percent of the values determined in accordance with Section 11.4.3 for SMSand SM1and Section 11.4.4 for SDSand SD1.

1615A.1.37. Earthquake Motion Measuring Instrumentation and Monitoring. [OSHPD 1 & 4] Modify ASCE 7 by the following:

Scope: For buildings with a seismic isolation system, a damping system or a lateral force resisting system (LFRS) not listed in ASCE 7 Table 12.2-1, earthquake motion measuring instrumentation and monitoring shall be required.

Instrumentation: There shall be a sufficient number of instruments to characterize the response of the building during an earthquake and shall include at least one tri-axial free field instrument or equivalent. A proposal for instrumentation and equipment specifications shall be forwarded to the enforcement agency for review and approval. The owner of the building shall be responsible for the implementation of the instrumentation program. Maintenance of the instrumentation and removal/processing of the records shall be the responsibility of the enforcement agency.

Monitoring: After every significant seismic events, where the ground shaking acceleration at the site exceeds 0.3g, or the acceleration at any monitored building level exceeds 0.8g, as measured by the seismic monitoring system in the building, the owner shall retain a structural engineer to make an inspection of the structural system.The inspection shall include viewing the performance of the building, reviewing the strong motion records, and a visual examination of the isolators, dampers and connections for deterioration, offset or physical damage. A report for each inspection, including conclusions on the continuing adequacy of the structural system, shall be submitted to the enforcement agency.

1615A.1.38 Operational Nonstructural Performance Level Requirements. [OSHPD 1 & 4] New buildings designed and constructed to this code shall be deemed to satisfy operational nonstructural performance level when:

  1. The facility has on-site supplies of water and holding tanks for wastewater, sufficient for 72 hours of emergency operations, which are integrated into the building plumbing systems. As an alternative, hook-ups to allow for the use of transportable sources of water and sanitary waste water disposal shall be permitted.
  2. An on-site emergency system as defined within Part 3, Title 24 is incorporated into the building electrical system for critical care areas. Additionally, the system shall provide for radiological service and an onsite fuel supply for 72 hours of acute care operation.
126
CALIFORNIA BUILDING CODE-MATRIX ADOPTION TABLE
CHAPTER 17 - STRUCTURAL TESTS AND SPECIAL INSPECTIONS
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCECCASLSLC
121-ACACSSSS/CC1234
Adopt entire chapter          X         
Adopt entire chapter as
amended (amended sections
listed below)		X XX     X          
Adopt only those sections that
are listed below		                    
Chapter/Section                    
1702 - Approved Agency  XX                
1704.1  XX                
1704.1.1X        X          
1704.6.2         X          
1711.1X                   
                     
127 128

CHAPTER 17
STRUCTURAL TESTS AND SPECIAL INSPECTIONS

SECTION 1701
GENERAL

1701.1 Scope. The provisions of this chapter shall govern the quality, workmanship and requirements for materials covered. Materials of construction and tests shall conform to the applicable standards listed in this code.

1701.2 New materials. New building materials, equipment, appliances, systems or methods of construction not provided for in this code, and any material of questioned suitability proposed for use in the construction of a building or structure, shall be subjected to the tests prescribed in this chapter and in the approved rules to determine character, quality and limitations of use.

1701.3 Used materials. The use of second-hand materials that meet the minimum requirements of this code for new materials shall be permitted.

SECTION 1702
DEFINITIONS

1702.1 General. The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meanings shown herein.

APPROVED AGENCY. An established and recognized agency regularly engaged in conducting tests or furnishing inspection services, when such agency has been approved. [HCD 1 & HCD 2] “Approved agency” shall mean “Listing agency” and “Testing agency” (See Chapter 2 definitions).

APPROVED FABRICATOR. An established and qualified person, firm or corporation approved by the building official pursuant to Chapter 17 of this code.

CERTIFICATE OF COMPLIANCE. A certificate stating that materials and products meet specified standards or that work was done in compliance with approved construction documents.

DESIGNATED SEISMIC SYSTEM. Those architectural, electrical and mechanical systems and their components that require design in accordance with Chapter 13 of ASCE 7 and for which the component importance factor, Ip, is greater than 1 in accordance with Section 13.1.3 of ASCE 7.

FABRICATED ITEM. Structural, load-bearing or lateral load-resisting assemblies consisting of materials assembled prior to installation in a building or structure, or subjected to operations such as heat treatment, thermal cutting, cold working or reforming after manufacture and prior to installation in a building or structure. Materials produced in accordance with standard specifications referenced by this code, such as rolled structural steel shapes, steel-reinforcing basis, masonry units, and wood structural panels or in accordance with a standard, listed in Chapter 35, which provides requirements for quality control done under the supervision of a third-party quality control agency shall not be considered “fabricated items.”

INSPECTION CERTIFICATE. An identification applied on a product by an approved agency containing the name of the manufacturer, the function and performance characteristics, and the name and identification of an approved agency that indicates that the product or material has been inspected and evaluated by an approved agency (see Section 1703.5 and “Label,” “Manufacturer’s designation” and “ Mark”).

INTUMESCENT FIRE-RESISTANT COATINGS. Thin film liquid mixture applied to substrates by brush, roller, spray or trowel which expands into a protective foamed layer to provide fire-resistant protection of the substrates when exposed to flame or intense heat.

MAIN WINDFORCE-RESISTING SYSTEM. An assemblage of structural elements assigned to provide support and stability for the overall structure. The system generally receives wind loading from more than one surface.

MASTIC FIRE-RESISTANT COATINGS. Liquid mixture applied to a substrate by brush, roller, spray or trowel that provides fire-resistant protection of a substrate when exposed to flame or intense heat.

SPECIAL INSPECTION. Inspection as herein required of the materials, installation, fabrication, erection or placement of components and connections requiring special expertise to ensure compliance with approved construction documents and referenced standards (see Section 1704).

SPECIAL INSPECTION, CONTINUOUS. The full-time observation of work requiring special inspection by an approved special inspector who is present in the area where the work is being performed.

SPECIAL INSPECTION, PERIODIC. The part-time or intermittent observation of work requiring special inspection by an approved special inspector who is present in the area where the work has been or is being performed and at the completion of the work.

SPRAYED FIRE-RESISTANT MATERIALS. Cementitious or fibrous materials that are sprayed to provide fire-resistant protection of the substrates.

STRUCTURAL OBSERVATION. The visual observation of the structural system by a registered design professional for general conformance to the approved construction documents. Structural observation does not include or waive the responsibility for the inspection required by Section 110, 1704 or other sections of this code.

SECTION 1703
APPROVALS

1703.1 Approved agency. An approved agency shall provide all information as necessary for the building official to determine that the agency meets the applicable requirements.

1703.1.1 Independence. An approved agency shall be objective, competent and independent from the contractor 129 responsible for the work being inspected. The agency shall also disclose possible conflicts of interest so that objectivity can be confirmed.

1703.1.2 Equipment. An approved agency shall have adequate equipment to perform required tests. The equipment shall be periodically calibrated.

1703.1.3 Personnel. An approved agency shall employ experienced personnel educated in conducting, supervising and evaluating tests and/or inspections.

1703.2 Written approval. Any material, appliance, equipment, system or method of construction meeting the requirements of this code shall be approved in writing after satisfactory completion of the required tests and submission of required test reports.

1703.3 Approved record. For any material, appliance, equipment, system or method of construction that has been approved, a record of such approval, including the conditions and limitations of the approval, shall be kept on file in the building official’s office and shall be open to public inspection at appropriate times.

1703.4 Performance. Specific information consisting of test reports conducted by an approved testing agency in accordance with standards referenced in Chapter 35, or other such information as necessary, shall be provided for the building official to determine that the material meets the applicable code requirements.

1703.4.1 Research and investigation. Sufficient technical data shall be submitted to the building official to substantiate the proposed use of any material or assembly. If it is determined that the evidence submitted is satisfactory proof of performance for the use intended, the building official shall approve the use of the material or assembly subject to the requirements of this code. The costs, reports and investigations required under these provisions shall be paid by the applicant.

1703.4.2 Research reports. Supporting data, where necessary to assist in the approval of materials or assemblies not specifically provided for in this code, shall consist of valid research reports from approved sources.

1703.5 Labeling. Where materials or assemblies are required by this code to be labeled, such materials and assemblies shall be labeled by an approved agency in accordance with Section 1703. Products and materials required to be labeled shall be labeled in accordance with the procedures set forth in Sections 1703.5.1 through 1703.5.3.

1703.5.1 Testing. An approved agency shall test a representative sample of the product or material being labeled to the relevant standard or standards. The approved agency shall maintain a record of the tests performed. The record shall provide sufficient detail to verify compliance with the test standard.

1703.5.2 Inspection and identification. The approved agency shall periodically perform an inspection, which shall be in-plant if necessary, of the product or material that is to be labeled. The inspection shall verify that the labeled product or material is representative of the product or material tested.

1703.5.3 Label information. The label shall contain the manufacturer’s or distributor’s identification, model number, serial number or definitive information describing the product or material’s performance characteristics and approved agency’s identification.

1703.6 Evaluation and follow-up inspection services. Where structural components or other items regulated by this code are not visible for inspection after completion of a prefabricated assembly, the applicant shall submit a report of each prefabricated assembly. The report shall indicate the complete details of the assembly, including a description of the assembly and its components, the basis upon which the assembly is being evaluated, test results and similar information and other data as necessary for the building official to determine conformance to this code. Such a report shall be approved by the building official.

1703.6.1 Follow-up inspection. The applicant shall provide for special inspections of fabricated items in accordance with Section 1704.2.

1703.6.2 Test and inspection records. Copies of necessary test and inspection records shall be filed with the building official.

SECTION 1704
SPECIAL INSPECTIONS

1704.1 General. Where application is made for construction as described in this section, the owner or the registered design professional in responsible charge acting as the owner’s agent shall employ one or more approved agencies to perform inspections during construction on the types of work listed under Section 1704. These inspections are in addition to the inspections identified in Section 110.

The special inspector shall be a qualified person who shall demonstrate competence, to the satisfaction of the building official, for the inspection of the particular type of construction or operation requiring special inspection. The registered design professional in responsible charge and engineers of record involved in the design of the project are permitted to act as the approved agency and their personnel are permitted to act as the special inspector for the work designed by them, provided those personnel meet the qualification requirements of this section to the satisfaction of the building official. The special inspector shall provide written documentation to the building official demonstrating his or her competence and relevant experience or training. Experience or training shall be considered relevant when the documented experience or training is related in complexity to the same type of special inspection activities for projects of similar complexity and material qualities. These qualifications are in addition to qualifications specified in other sections of this code.

Exceptions:

  1. Special inspections are not required for work of a minor nature or as warranted by conditions in the jurisdiction as approved by the building official.130
  2. Special inspections are not required for building components unless the design involves the practice of professional engineering or architecture as defined by applicable state statutes and regulations governing the professional registration and certification of engineers or architects.
  3. Unless otherwise required by the building official, special inspections are not required for Group U occupancies that are accessory to a residential occupancy including, but not limited to, those listed in Section 312.1.
  4. [HCD 1] The provisions of Health and Safety Code Division 13, Part 6 and the California Code of Regulations, Title 25, Division 1, Chapter 3, commencing with Section 3000, shall apply to the construction and inspection of factory-built housing as defined in Health and Safety Code Section 19971.

1704.1.1 Statement of special inspections. The applicant shall submit a statement of special inspections prepared by the registered design professional in responsible charge in accordance with Section 107.1 Chapter 1, Division II, as a conditionfor issuance. This statement shall be in accordance with Section 1705.

Exceptions:

  1. A statement of special inspections is not required for structures designed and constructed in accordance with the conventional construction provisions of Section 2308. [OSHPD 2] Not permitted by OSHPD.
  2. The statement of special inspections is permitted to be prepared by a qualified person approved by the building official for construction not designed by a registered design professional.

1704.1.2 Report requirement. Special inspectors shall keep records of inspections. The special inspector shall furnish inspection reports to the building official and to the registered design professional in responsible charge. Reports shall indicate that work inspected was or was not completed in conformance to approved construction documents. Discrepancies shall be brought to the immediate attention of the contractor for correction. If they are not corrected, the discrepancies shall be brought to the attention of the building official and to the registered design professional in responsible charge prior to the completion of that phase of the work. A final report documenting required special inspections and correction of any discrepancies noted in the inspections shall be submitted at a point in time agreed upon prior to the start of work by the applicant and the building official.

1704.2 Inspection of fabricators. Where fabrication of structural load-bearing members and assemblies is being performed on the premises of a fabricator's shop, special inspection of the fabricated items shall be required by this section and as required elsewhere in this code.

1704.2.1 Fabrication and implementation procedures. The special inspector shall verify that the fabricator maintains detailed fabrication and quality control procedures that provide a basis for inspection control of the workmanship and the fabricator's ability to conform to approved construction documents and referenced standards. The special inspector shall review the procedures for completeness and adequacy relative to the code requirements for the fabricator's scope of work.

Exception: Special inspections as required by Section 1704.2 shall not be required where the fabricator is approved in accordance with Section 1704.2.2.

1704.2.2 Fabricator approval. Special inspections required by Section 1704 are not required where the work is done on the premises of a fabricator registered and approved to perform such work without special inspection. Approval shall be based upon review of the fabricator's written procedural and quality control manuals and periodic auditing of fabrication practices by an approved special inspection agency. At completion of fabrication, the approved fabricator shall submit a certificate of compliance to the building official stating that the work was performed in accordance with the approved construction documents.

1704.3 Steel construction. The special inspections for steel elements of buildings and structures shall be as required by Section 1704.3 and Table 1704.3.

Exceptions:

  1. Special inspection of the steel fabrication process shall not be required where the fabricator does not perform any welding, thermal cutting or heating operation of any kind as part of the fabrication process. In such cases, the fabricator shall be required to submit a detailed procedure for material control that demonstrates the fabricator's ability to maintain suitable records and procedures such that, at any time during the fabrication process, the material specification, grade and mill test reports for the main stress-carrying elements are capable of being determined.
  2. The special inspector need not be continuously present during welding of the following items, provided the materials, welding procedures and qualifications of welders are verified prior to the start of the work; periodic inspections are made of the work in progress and a visual inspection of all welds is made prior to completion or prior to shipment of shop welding.
    1. Single-pass fillet welds not exceeding 5/16 inch (7.9 mm) in size.
    2. Floor and roof deck welding.
    3. Welded studs when used for structural diaphragm.
    4. Welded sheet steel for cold-formed steel members.
    5. Welding of stairs and railing systems.

1704.3.1 Welding. Welding inspection and welding inspector qualification shall be in accordance with this section.

1704.3.1.1 Structural steel. Welding inspection and welding inspector qualification for structural steel shall be in accordance with AWS D1.1.

131
TABLE 1704.3
REQUIRED VERIFICATION AND INSPECTION OF STEEL CONSTRUCTION
VERIFICATION AND INSPECTIONCONTINUOUSPERIODICREFERENCED
STANDARDa		IBC REFERENCE
For SI: 1 inch = 25.4 mm.
a. Where applicable, see also Section 1707.1, Special inspection for seismic resistance.
1. Material verification of high-strength bolts, nuts and
washers:
a. Identification markings to conform to ASTM
standards specified in the approved
construction documents.		—XAISC 360,
Section A3.3 and
applicable ASTM
material standards		 
b. Manufacturer's certificate of compliance
required.		—X——
2. Inspection of high-strength bolting:
a. Snug-tight joints.—XAISC 360,
Section M2.5		1704.3.3
b. Pretensioned and slip-critical joints using
turn-of-nut with matchmarking, twist-off bolt or
direct tension indicator methods of installation.		—X
c. Pretensioned and slip-critical joints using
turn-of-nut without matchmarking or calibrated
wrench methods of installation.		X—
3. Material verification of structural steel and
cold-formed steel deck:
a. For structural steel, identification markings to
conform to AISC 360.		—XAISC 360,
Section M5.5
b.For other steel, identification markings to conform
to ASTM standards specified in the approved
construction documents.		—XApplicable ASTM
material standards
c.Manufacturer's certified test reports.—X  
4. Material verification of weld filler materials:
a.Identification markings to conform to AWS
specification in the approved construction
documents.		—XAISC 360,
Section A3.5 and
applicable AWS
A5 documents		—
b.Manufacturer's certificate of compliance required.—X——
5. Inspection of welding:
a. Structural steel and cold-formed steel deck:
1) Complete and partial joint penetration groove
welds.		X—AWS D1.11704.3.1
2) Multipass fillet welds.X—
3) Single-pass fillet welds > 5/16″X—
4) Plug and slot welds.X—
5) Single-pass fillet welds ≤5/16″X—
6) Floor and roof deck welds.—XAWS D1.3132
b. Reinforcing steel:   —
1) Verification of weldability of reinforcing steel
other than ASTM A 706.		—XAWS D1.4 ACI 318: Section 3.5.2
2) Reinforcing steel resisting flexural and axial
forces in intermediate and special moment
frames, and boundary elements of special
structural walls of concrete and shear
reinforcement.		X—
3) Shear reinforcement.X—
4) Other reinforcing steel.—X
6. Inspection of steel frame joint details for compliance:
a. Details such as bracing and stiffening.—X—1704.3.2
b. Member locations.—X
c. Application of joint details at each connection—X

1704.3.1.2 Cold-formed steel. Welding inspection and welding inspector qualification for cold-formed steel floor and roof decks shall be in accordance with AWS D1.3.

1704.3.1.3 Reinforcing steel. Welding inspection and welding inspector qualification for reinforcing steel shall be in accordance with AWS D1.4 and ACI 318.

1704.3.2 Details. The special inspector shall perform an inspection of the steel frame to verify compliance with the details shown on the approved construction documents, such as bracing, stiffening, member locations and proper application of joint details at each connection.

1704.3.3 High-strength bolts. Installation of high-strength bolts shall be inspected in accordance with AISC 360.

1704.3.3.1 General. While the work is in progress, the special inspector shall determine that the requirements for bolts, nuts, washers and paint; bolted parts and installation and tightening in such standards are met. For bolts requiring pretensioning, the special inspector shall observe the preinstallation testing and calibration procedures when such procedures are required by the installation method or by project plans or specifications; determine that all plies of connected materials have been drawn together and properly snugged and monitor the installation of bolts to verify that the selected procedure for installation is properly used to tighten bolts. For joints required to be tightened only to the snug-tight condition, the special inspector need only verify that the connected materials have been drawn together and properly snugged.

1704.3.3.2 Periodic monitoring. Monitoring of bolt installation for pretensioning is permitted to be performed on a periodic basis when using the turn-of-nut method with matchmarking techniques, the direct tension indicator method or the alternate design fastener (twist-off bolt) method. Joints designated as snug tight need be inspected only on a periodic basis.

1704.3.3.3 Continuous monitoring. Monitoring of bolt installation for pretensioning using the calibrated wrench method or the turn-of-nut method without matchmarking shall be performed on a continuous basis.

1704.3.4 Cold-formed steel trusses spanning 60 feet or greater. Where a cold-formed steel truss clear span is 60 feet (18 288 mm) or greater, the special inspector shall verify that the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing are installed in accordance with the approved truss submittal package.

1704.4 Concrete construction. The special inspections and verifications for concrete construction shall be as required by this section and Table 1704.4.

Exception: Special inspections shall not be required for:

  1. Isolated spread concrete footings of buildings three stories or less above grade plane that are fully supported on earth or rock.133
  2. Continuous concrete footings supporting walls of buildings three stories or less above grade plane that are fully supported on earth or rock where:
    1. The footings support walls of light-frame construction;
    2. The footings are designed in accordance with Table 1809.7; or
    3. The structural design of the footing is based on a specified compressive strength, f'c, no greater than 2,500 pounds per square inch (psi) (17.2 MPa), regardless of the compressive strength specified in the construction documents or used in the footing construction.
  3. Nonstructural concrete slabs supported directly on the ground, including prestressed slabs on grade, where the effective prestress in the concrete is less than 150 psi (1.03 MPa).
  4. Concrete foundation walls constructed in accordance with Table 1807.1.6.2.
  5. Concrete patios, driveways and sidewalks, on grade.
TABLE 1704.4
REQUIRED VERIFICATION AND INSPECTION OF CONCRETE CONSTRUCTION
VERIFICATION AND INSPECTIONCONTINUOUSPERIODICREFERENCED
STANDARDa		IBC REFERENCE
For SI: 1 inch = 25.4 mm.
a. Where applicable, see also Section 1707.1, Special inspection for seismic resistance.
1. Inspection of reinforcing steel, including
prestressing tendons, and placement.		—XACI 318: 3.5, 7.1-7.71913.4
2. Inspection of reinforcing steel welding in
accordance with Table 1704.3, Item 5b.		——AWS D1.4
ACI 318: 3.5.2		—
3. Inspection of bolts to be installed in concrete
prior to and during placement of concrete where
allowable loads have been increased or where strength design is used.		X—ACI 318:
8.1.3, 21.2.8		1911.5,
1912.1
4. Inspection of anchors installed in hardened
concrete.		—XACI 318:
3.8.6, 8.1.3, 21.2.8		1912.1
5. Verifying use of required design mix.—XACI 318: Ch. 4, 5.2-5.41904.2.2, 1913.2,
1913.3
6. At the time fresh concrete is sampled to fabricate
specimens for strength tests, perform slump and
air content tests, and determine the temperature
of the concrete.		X—ASTM C 172
ASTM C 31
ACI 318: 5.6, 5.8		1913.10
7. Inspection of concrete and shotcrete placement
for proper application techniques.		X—ACI 318: 5.9, 5.101913.6, 1913.7, 1913.8
8. Inspection for maintenance of specified curing
temperature and techniques.		—XACI 318: 5.11-5.131913.9
9. Inspection of prestressed concrete:
a. Application of prestressing forces.
b. Grouting of bonded prestressing tendons in
the seismic-force-resisting system.		X
X		—ACI 318: 18.20
ACI 318: 18.18.4		—
10. Erection of precast concrete members.—XACI 318: Ch. 16—
11. Verification of in-situ concrete strength, prior to
stressing of tendons in posttensioned concrete
and prior to removal of shores and forms from
beams and structural slabs.		—XACI 318: 6.2—
12. Inspect formwork for shape, location and
dimensions of the concrete member being
formed.		—XACI 318: 6.1.1—
134

1704.4.1 Materials. In the absence of sufficient data or documentation providing evidence of conformance to quality standards for materials in Chapter 3 of ACI 318, the building official shall require testing of materials in accordance with the appropriate standards and criteria for the material in Chapter 3 of ACI 318. Weldability of reinforcement, except that which conforms to ASTM A 706, shall be determined in accordance with the requirements of Section 3.5.2 of ACI 318.

1704.5 Masonry construction. Masonry construction shall be inspected and verified in accordance with the requirements of Sections 1704.5.1 through 1704.5.3, depending on the occupancy category of the building or structure.

Exception: Special inspections shall not be required for:

  1. Empirically designed masonry, glass unit masonry or masonry veneer designed by Section 2109, 2110 or Chapter 14, respectively, or by Chapter 5, 6 or 7 of TMS 402/ACI 530/ASCE 5, respectively, when they are part of structures classified as Occupancy Category I, II or III in accordance with Section 1604.5.
  2. Masonry foundation walls constructed in accordance with Table 1807.1.6.3(1), 1807.1.6.3(2), 1807.1.6.3(3) or 1807.1.6.3.(4).
  3. Masonry fireplaces, masonry heaters or masonry chimneys installed or constructed in accordance with Section 2111, 2112 or 2113, respectively.

1704.5.1 Empirically designed masonry, glass unit masonry and masonry veneer in Occupancy Category IV. The minimum special inspection program for empirically designed masonry, glass unit masonry or masonry veneer designed by Section 2109, 2110 or Chapter 14, respectively, or by Chapter 5,6 or 7 of TMS 402/ACI 530/ASCE 5, respectively, in structures classified as Occupancy Category IV, in accordance with Section 1604.5, shall comply with Table 1704.5.1.

1704.5.2 Engineered masonry in Occupancy Category I, II or III. The minimum special inspection program for masonry designed by Section 2107 or 2108 or by chapters other than Chapter 5, 6 or 7 of TMS 402/ACI 530/ASCE 5 in structures classified as Occupancy Category I, II or III, in accordance with Section 1604.5, shall comply with Table 1704.5.1.

1704.5.3 Engineered masonry in Occupancy Category IV. The minimum special inspection program for masonry designed by Section 2107 or 2108 or by chapters other than Chapter 5, 6 or 7 of TMS 402/ACI 530/ASCE 5 in structures classified as Occupancy Category IV, in accordance with Section 1604.5, shall comply with Table 1704.5.3.

1704.6 Wood construction. Special inspections of the fabrication process of prefabricated wood structural elements and assemblies shall be in accordance with Section 1704.2. Special inspections of site-built assemblies shall be in accordance with this section.

1704.6.1 High-load diaphragms. High-load diaphragms designed in accordance with Table 2306.2.1(2) shall be installed with special inspections as indicated in Section 1704.1. The special inspector shall inspect the wood structural panel sheathing to ascertain whether it is of the grade and thickness shown on the approved building plans. Additionally, the special inspector must verify the nominal size of framing members at adjoining panel edges, the nail or staple diameter and length, the number of fastener lines and that the spacing between fasteners in each line and at edge margins agrees with the approved building plans.

1704.6.2 Metal-plate-connected wood trusses spanning 60 feet or greater. Where a truss clear span is 60 feet (18288 mm) or greater, the special inspector shall verify that the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing are installed in accordance with the approved truss submittal package.

1704.6.2 Manufactured trusses and assemblies. [OSHPD 2] The fabrication of trusses and other assemblages constructed using wood and metal members, or using light metal plate connectors, shall be continuously inspected by a qualified inspector approved by the enforcement agency. The inspector shall furnish the architect, structural engineer and the enforcement agency with a report that the lumber species, grades and moisture content; type of glue, temperature and gluing procedure; type of metal members and metal plate connectors; and the workmanship conform in every material respect with the duly approved plans and specifications. Each inspected truss shall be stamped by the inspector with an identifying mark.

1704.7 Soils. Special inspections for existing site soil conditions, fill placement and load-bearing requirements shall be as required by this section and Table 1704.7. The approved geotechnical report, and the construction documents prepared by the registered design professionals shall be used to determine compliance. During fill placement, the special inspector shall determine that proper materials and procedures are used in accordance with the provisions of the approved geotechnical report.

Exception: Where Section 1803 does not require reporting of materials and procedures for fill placement, the special inspector shall verify that the in-place dry density of the compacted fill is not less than 90 percent of the maximum dry density at optimum moisture content determined in accordance with ASTM D 1557.

1704.8 Driven deep foundations. Special Inspections shall be performed during installation and testing of driven deep foundation elements as required by Table 1704.8. The approved geotechnical report, and the construction documents prepared by the registered design professionals, shall be used to determine compliance.

1704.9 Cast-in-place deep foundations. Special inspections shall be performed during installation and testing of cast-in-place deep foundation elements as required by Table 1704.9. The approved geotechnical report, and the construction documents prepared by the registered design professionals, shall be used to determine compliance.

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TABLE 1704.5.1
LEVEL 1 REQUIRED VERIFICATION AND INSPECTION OF MASONRY CONSTRUCTION
VERIFICATION AND INSPECTIONFREQUENCY OF INSPECTIONREFERENCE FOR CRITERIA
CONTINUOUSPERIODICIBC SECTIONTMS 402/ACI
530/ASCE 5a		TMS 602/ACI
530.1/ASCE 6a
For SI: °C = [(°F) - 32]/1.8.
a. The specific standards referenced are those listed in Chapter 35.
1. Compliance with required inspection provisions of the construction documents and the approved submittals shall be verified.—X——Art. 1.5
2. Verification of f'm and f'AAC prior to construction except where specifically exempted by this code.—X——Art. 1.4B
3. Verification of slump flow and VSI as delivered to the site for self-consolidating grout.X———Art. 1.5B.1.b.3
4. As masonry construction begins, the following shall be verified to ensure compliance:
a. Proportions of site-prepared mortar.—X——Art. 2.6A
b. Construction of mortar joints.—X——Art. 3.3B
c. Location of reinforcement, connectors, prestressing tendons and anchorages.—X——Art. 3.4, 3.6A
d. Prestressing technique.—X——Art. 3.6B
e. Grade and size of prestressing tendons and anchorages.—X——Art. 2.4B, 2.4H
5. During construction the inspection program shall verify:
a. Size and location of structural elements.—X——Art. 3.3F
b. Type, size and location of anchors, including other details of anchorage of masonry to structural members, frames or other construction.—X—Sec. 1.2.2(e), 1.16.1—
c. Specified size, grade and type of reinforcement, anchor bolts, prestressing tendons and anchorages.—X—Sec. 1.15Art. 2.4, 3.4
d. Welding of reinforcing bars.X——Sec. 2.1.9.7.2, 3.3.3.4(b)—
e. Preparation, construction and protection of masonry during cold weather (temperature below 40°F) or hot weather (temperature above 90°F).—XSec. 2104.3, 2104.4—Art. 1.8C, 1.8D
f. Application and measurement of prestressing force.X———Art. 3.6B136
6. Prior to grouting, the following shall be verified to ensure compliance:
a. Grout space is clean.—X——Art. 3.2D
b. Placement of reinforcement and connectors, and prestressing tendons and anchorages.—X—Sec. 1.13Art. 3.4
c. Proportions of site-prepared grout and prestressing grout for bonded tendons.—X——Art. 2.6B
d. Construction of mortar joints.—X——Art. 3.3B
7. Grout placement shall be verified to ensure compliance:X———Art. 3.5
a. Grouting of prestressing bonded tendons.X———Art. 3.6C
8. Preparation of any required grout specimens, mortar specimens and/or prisms shall be observed.—XSec. 2105.2.2, 2105.3—Art. 1.4
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TABLE 1704.5.3
LEVEL 2 REQUIRED VERIFICATION AND INSPECTION OF MASONRY CONSTRUCTION
VERIFICATION AND INSPECTIONCONTINUOUSPERIODICREFERENCE FOR CRITERIA
IBC SECTIONTMS 402/ACI 530/ASCE 5aTMS 602/ACI 530.1/ASCE 6a
For SI: °C = [(°F) - 32]/1.8, 1 square foot = 0.0929 m2
a. The specific standards referenced are those listed in Chapter 35.
1. Compliance with required inspection provisions of the construction documents and the approved submittals.—X——Art. 1.5
2. Verification of f'm and f'AAC prior to construction and for every 5,000 square feet during construction.—X——Art. 1.4B
3. Verification of proportions of materials in premixed or preblended mortar and grout as delivered to the site.—X——Art. 1.5B
4. Verification of slump flow and VSI as delivered to the site for self-consolidating grout.X———Art. 1.5B.1.b.3
5. The following shall be verified to ensure compliance:
a. Proportions of site-prepared mortar, grout and prestressing grout for bonded tendons.—X——Art. 2.6A
b. Placement of masonry units and construction of mortar joints.—X——Art. 3.3B
c. Placement of reinforcement, connectors and prestressing tendons and anchorages.—X—Sec. 1.15Art. 3.4, 3.6A
d. Grout space prior to grout.X———Art. 3.2D
e. Placement of grout.X———Art. 3.5
f. Placement of prestressing grout.X———Art. 3.6C
g. Size and location of structural elements.—X——Art. 3.3F
h. Type, size and location of anchors, including other details of anchorage of masonry to structural members, frames or other construction.X——Sec. 1.2.2(e), 1.16.1—
i. Specified size, grade and type of reinforcement, anchor bolts, prestressing tendons and anchorages.—X—Sec. 1.15Art. 2.4, 3.4
j. Welding of reinforcing bars.X——Sec. 2.1.9.7.2, 3.3.3.4 (b)—
k. Preparation, construction and protection of masonry during cold weather (temperature below 40°F) or hot weather (temperature above 90°F).—XSec. 2104.3, 2104.4—Art. 1.8C, 1.8D
l. Application and measurement of prestressing force.X———Art. 3.6B
6. Preparation of any required grout specimens and/or prisms shall be observed.X—Sec. 2105.2.2, 2105.3—Art. 1.4
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TABLE 1704.7
REQUIRED VERIFICATION AND INSPECTION OF SOILS
VERIFICATION AND INSPECTION TASKCONTINUOUS DURING TASK LISTEDPERIODICALLY DURING TASK LISTED
1. Verify materials below shallow foundations are adequate to achieve the design bearing capacity.—X
2. Verify excavations are extended to proper depth and have reached proper material.—X
3. Perform classification and testing of compacted fill materials.—X
4. Verify use of proper materials, densities and lift thicknesses during placement and compaction of compacted fill.X—
5. Prior to placement of compacted fill, observe subgrade and verify that site has been prepared properly.—X
TABLE 1704.8
VERIFICATION AND INSPECTION OF DRIVEN DEEP FOUNDATION ELEMENTS
VERIFICATION AND INSPECTION TASKCONTINUOUS DURING TASK LISTEDPERIODICALLY DURING TASK LISTED
1. Verify element materials, sizes and lengths comply with the requirements.X—
2. Determine capacities of test elements and conduct additional load tests, as required.X—
3. Observe driving operations and maintain complete and accurate records for each element.X—
4. Verify placement locations and plumbness, confirm type and size of hammer, record number of blows per foot of penetration, determine required penetrations to achieve design capacity, record tip and butt elevations and document any damage to foundation element.X—
5. For steel elements, perform additional inspections in accordance with Section 1704.3.——
6. For concrete elements and concrete-filled elements, perform additional inspections in accordance with Section 1704.4.——
7. For specialty elements, perform additional inspections as determined by the registered design professional in responsible charge.——
TABLE 1704.9
REQUIRED VERIFICATION AND INSPECTION OF CAST-IN-PLACE DEEP FOUNDATION ELEMENTS
VERIFICATION AND INSPECTION TASKCONTINUOUS DURING TASK LISTEDPERIODICALLY DURING TASK LISTED
1. Observe drilling operations and maintain complete and accurate records for each element.X—
2. Verify placement locations and plumbness, confirm element diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable) and adequate end-bearing strata capacity. Record concrete or grout volumes.X—
3. For concrete elements, perform additional inspections in accordance with Section 1704.4.——
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1704.10 Helical pile foundations. Special inspections shall be performed continuously during installation of helical pile foundations. The information recorded shall include installation equipment used, pile dimensions, tip elevations, final depth, final installation torque and other pertinent installation data as required by the registered design professional in responsible charge. The approved geotechnical report and the construction documents prepared by the registered design professional shall be used to determine compliance.

1704.11 Vertical masonry foundation elements. Special inspection shall be performed in accordance with Section 1704.5 for vertical masonry foundation elements.

1704.12 Sprayed fire-resistant materials. Special inspections for sprayed fire-resistant materials applied to floor, roof and wall assemblies and structural members shall be in accordance with Sections 1704.12.1 through 1704.12.6. Special inspections shall be based on the fire-resistance design as designated in the approved construction documents. The tests set forth in this section shall be based on samplings from specific floor, roof and wall assemblies and structural members. Special inspections shall be performed after the rough installation of electrical, automatic sprinkler, mechanical and plumbing systems and suspension systems for ceilings, where applicable.

1704.12.1 Physical and visual tests. The special inspections shall include the following tests and observations to demonstrate compliance with the listing and the fire-resistance rating:

  1. Condition of substrates.
  2. Thickness of application.
  3. Density in pounds per cubic foot (kg/m3).
  4. Bond strength adhesion/cohesion.
  5. Condition of finished application.

1704.12.2 Structural member surface conditions. The surfaces shall be prepared in accordance with the approved fire-resistance design and the written instructions of approved manufacturers. The prepared surface of structural members to be sprayed shall be inspected before the application of the sprayed fire-resistant material.

1704.12.3 Application. The substrate shall have a minimum ambient temperature before and after application as specified in the written instructions of approved manufacturers. The area for application shall be ventilated during and after application as required by the written instructions of approved manufacturers.

1704.12.4 Thickness. No more than 10 percent of the thickness measurements of the sprayed fire-resistant materials applied to floor, roof and wall assemblies and structural members shall be less than the thickness required by the approved fire-resistance design, but in no case less than the minimum allowable thickness required by Section 1704.12.4.1.

1704.12.4.1 Minimum allowable thickness. For design thicknesses 1 inch (25 mm) or greater, the minimum allowable individual thickness shall be the design thickness minus ¼ inch (6.4 mm). For design thicknesses less than 1 inch (25 mm), the minimum allowable individual thickness shall be the design thickness minus 25 percent. Thickness shall be determined in accordance with ASTM E 605. Samples of the sprayed fire-resistant materials shall be selected in accordance with Sections 1704.12.4.2 and 1704.12.4.3.

1704.12.4.2 Floor, roof and wall assemblies. The thickness of the sprayed fire-resistant material applied to floor, roof and wall assemblies shall be determined in accordance with ASTM E 605, making not less than four measurements for each 1,000 square feet (93 m2) of the sprayed area in each story or portion thereof.

1704.12.4.2.1 Cellular decks. Thickness measurements shall be selected from a square area, 12 inches by 12 inches (305 mm by 305 mm) in size. A minimum of four measurements shall be made, located symmetrically within the square area.

1704.12.4.2.2 Fluted decks. Thickness measurements shall be selected from a square area, 12 inches by 12 inches (305 mm by 305 mm) in size. A minimum of four measurements shall be made, located symmetrically within the square area, including one each of the following: valley, crest and sides. The average of the measurements shall be reported.

1704.12.4.3 Structural members. The thickness of the sprayed fire-resistant material applied to structural members shall be determined in accordance with ASTM E 605. Thickness testing shall be performed on not less than 25 percent of the structural members on each floor.

1704.12.4.3.1 Beams and girders. At beams and girders thickness measurements shall be made at nine locations around the beam or girder at each end of a 12-inch (305 mm) length.

1704.12.4.3.2 Joists and trusses. At joists and trusses, thickness measurements shall be made at seven locations around the joist or truss at each end of a 12-inch (305 mm) length.

1704.12.4.3.3 Wide-flanged columns. At wide-flanged columns, thickness measurements shall be made at 12 locations around the columns at each end of a 12-inch (305 mm) length.

1704.12.4.3.4 Hollow structural section and pipe columns. At hollow structural section and pipe columns, thickness measurements shall be made at a minimum of four locations around the column at each end of a 12-inch (305 mm) length.

1704.12.5 Density. The density of the sprayed fire-resistant material shall not be less than the density specified in the approved fire-resistance design. Density of the sprayed fire-resistance material shall be determined in accordance with ASTM E 605. The test samples for determining the density of the sprayed fire-resistant materials shall be selected as follows:

  1. From each floor, roof and wall assembly at the rate of not less than one sample for every 2,500 square feet (232 m2) or portion thereof of the sprayed area in each story.140
  2. From beams, girders, trusses and columns at the rate of not less than one sample for each type of structural member for each 2,500 square feet (232 m2) of floor area or portion thereof in each story.

1704.12.6 Bond strength. The cohesive/adhesive bond strength of the cured sprayed fire-resistant material applied to floor, roof and wall assemblies and structural members shall not be less than 150 pounds per square foot (psf) (7.18 kN/m2). The cohesive/adhesive bond strength shall be determined in accordance with the field test specified in ASTME 736 by testing in-place samples of the sprayed fire-resistant material selected in accordance with Sections 1704.12.6.1 through 1704.12.6.3.

1704.12.6.1 Floor, roof and wall assemblies. The test samples for determining the cohesive/adhesive bond strength of the sprayed fire-resistant materials shall be selected from each floor, roof and wall assembly at the rate of not less than one sample for every 2,500 square feet (232 m2) of the sprayed area in each story or portion thereof.

1704.12.6.2 Structural members. The test samples for determining the cohesive/adhesive bond strength of the sprayed fire-resistant materials shall be selected from beams, girders, trusses, columns and other structural members at the rate of not less than one sample for each type of structural member for each 2,500 square feet (232 m2) of floor area or portion thereof in each story.

1704.12.6.3 Primer, paint and encapsulant bond tests. Bond tests to qualify a primer, paint or encapsulant shall be conducted when the sprayed fire-resistant material is applied to a primed, painted or encapsulated surface for which acceptable bond-strength performance between these coatings and the fire-resistant material has not been determined. A bonding agent approved by the SFRM manufacturer shall be applied to a primed, painted or encapsulated surface where the bond strengths are found to be less than required values.

1704.13 Mastic and intumescent fire-resistant coatings. Special inspections for mastic and intumescent fire-resistant coatings applied to structural elements and decks shall be in accordance with AWCI 12-B. Special inspections shall be based on the fire-resistance design as designated in the approved construction documents.

1704.14 Exterior insulation and finish systems (EIFS). Special inspections shall be required for all EIFS applications.

Exceptions:

  1. Special inspections shall not be required for EIFS applications installed over a water-resistive barrier with a means of draining moisture to the exterior.
  2. Special inspections shall not be required for EIFS applications installed over masonry or concrete walls.

1704.14.1 Water-resistive barrier coating. A water-resistive barrier coating complying with ASTM E 2570 requires special inspection of the water-resistive barrier coating when installed over a sheathing substrate.

1704.15 Special cases. Special inspections shall be required for proposed work that is, in the opinion of the building official, unusual in its nature, such as, but not limited to, the following examples:

  1. Construction materials and systems that are alternatives to materials and systems prescribed by this code.
  2. Unusual design applications of materials described in this code.
  3. Materials and systems required to be installed in accordance with additional manufacturer's instructions that prescribe requirements not contained in this code or in standards referenced by this code.

[F] 1704.16 Special inspection for smoke control. Smoke control systems shall be tested by a special inspector.

[F] 1704.16.1 Testing scope. The test scope shall be as follows:

  1. During erection of ductwork and prior to concealment for the purposes of leakage testing and recording of device location.
  2. Prior to occupancy and after sufficient completion for the purposes of pressure difference testing, flow measurements and detection and control verification.

[F] 1704.16.2 Qualifications. Special inspection agencies for smoke control shall have expertise in fire protection engineering, mechanical engineering and certification as air balancers.

SECTION 1705
STATEMENT OF SPECIAL INSPECTIONS

1705.1 General. Where special inspection or testing is required by Section 1704, 1707 or 1708, the registered design professional in responsible charge shall prepare a statement of special inspections in accordance with Section 1705 for submittal by the applicant (see Section 1704.1.1).

1705.2 Content of statement of special inspections. The statement of special inspections shall identify the following:

  1. The materials, systems, components and work required to have special inspection or testing by the building official or by the registered design professional responsible for each portion of the work.
  2. The type and extent of each special inspection.
  3. The type and extent of each test.
  4. Additional requirements for special inspection or testing for seismic or wind resistance as specified in Section 1705.3, 1705.4, 1707 or 1708.
  5. For each type of special inspection, identification as to whether it will be continuous special inspection or periodic special inspection.

1705.3 Seismic resistance. The statement of special inspections shall include seismic requirements for cases covered in Sections 1705.3.1 through 1705.3.5.

Exception: Seismic requirements are permitted to be excluded from the statement of special inspections for

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structures designed and constructed in accordance with the following:

  1. The structure consists of light-frame construction; the design spectral response acceleration at short periods, SDS, as determined in Section 1613.5.4, does not exceed 0.5g; and the height of the structure does not exceed 35 feet (10 668 mm) above grade plane; or
  2. The structure is constructed using a reinforced masonry structural system or reinforced concrete structural system; the design spectral response acceleration at short periods, SDS, as determined in Section 1613.5.4, does not exceed 0.5g, and the height of the structure does not exceed 25 feet (7620 mm) above grade plane; or
  3. Detached one- or two-family dwellings not exceeding two stories above grade plane, provided the structure does not have any of the following plan or vertical irregularities in accordance with Section 12.3.2 of ASCE 7:
    1. Torsional irregularity.
    2. Nonparallel systems.
    3. Stiffness irregularity—extreme soft story and soft story.
    4. Discontinuity in capacity—weak story.

1705.3.1 Seismic-force-resisting systems. The seismic-force-resisting systems in structures assigned to Seismic Design Category C, D, E or F, in accordance with Section 1613.

Exception: Requirements for the seismic-force-resisting system are permitted to be excluded from the statement of special inspections for steel systems in structures assigned to Seismic Design Category C that are not specifically detailed for seismic resistance, with a response modification coefficient, R, of 3 or less, excluding cantilever column systems.

1705.3.2 Designated seismic systems. Designated seismic systems in structures assigned to Seismic Design Category D, E or F.

1705.3.3 Seismic Design Category C. The following additional systems and components in structures assigned to Seismic Design Category C:

  1. Heating, ventilating and air-conditioning (HVAC) ductwork containing hazardous materials and anchorage of such ductwork.
  2. Piping systems and mechanical units containing flammable, combustible or highly toxic materials.
  3. Anchorage of electrical equipment used for emergency or standby power systems.

1705.3.4 Seismic Design Category D. The following additional systems and components in structures assigned to Seismic Design Category D:

  1. Systems required for Seismic Design Category C.
  2. Exterior wall panels and their anchorage.
  3. Suspended ceiling systems and their anchorage.
  4. Access floors and their anchorage.
  5. Steel storage racks and their anchorage, where the importance factor is equal to 1.5 in accordance with Section 15.5.3 of ASCE 7.

1705.3.5 Seismic Design Category E or F. The following additional systems and components in structures assigned to Seismic Design Category E or F:

  1. Systems required for Seismic Design Categories C and D.
  2. Electrical equipment.

1705.3.6 Seismic requirements in the statement of special inspections. When Sections 1705.3 through 1705.3.5 specify that seismic requirements be included, the statement of special inspections shall identify the following:

  1. The designated seismic systems and seismic-force-resisting systems that are subject to special inspections in accordance with Sections 1705.3 through 1705.3.5.
  2. The additional special inspections and testing to be provided as required by Sections 1707 and 1708 and other applicable sections of this code, including the applicable standards referenced by this code.

1705.4 Wind resistance. The statement of special inspections shall include wind requirements for structures constructed in the following areas:

  1. In wind Exposure Category B, where the 3-second-gust basic wind speed is 120 miles per hour (mph) (52.8 m/s) or greater.
  2. In wind Exposure Category C or D, where the 3-second-gust basic wind speed is 110 mph (49 m/s) or greater.

1705.4.1 Wind requirements in the statement of special inspections. When Section 1705.4 specifies that wind requirements be included, the statement of special inspections shall identify the main wind-force-resisting systems and wind-resisting components subject to special inspections as specified in Section 1705.4.2.

1705.4.2 Detailed requirements. The statement of special inspections shall include at least the following systems and components:

  1. Roof cladding and roof framing connections.
  2. Wall connections to roof and floor diaphragms and framing.
  3. Roof and floor diaphragm systems, including collectors, drag struts and boundary elements.
  4. Vertical wind-force-resisting systems, including braced frames, moment frames and shear walls.
  5. Wind-force-resisting system connections to the foundation.142
  6. Fabrication and installation of systems or components required to meet the impact-resistance requirements of Section 1609.1.2.

Exception: Fabrication of manufactured systems or components that have a label indicating compliance with the wind-load and impact-resistance requirements of this code.

SECTION 1706
SPECIAL INSPECTIONS FOR
WIND REQUIREMENTS

1706.1 Special inspections for wind requirements. Special inspections itemized in Sections 1706.2 through 1706.4, unless exempted by the exceptions to Section 1704.1, are required for buildings and structures constructed in the following areas:

  1. In wind Exposure Category B, where the 3-second-gust basic wind speed is 120 miles per hour (52.8 m/sec) or greater.
  2. In wind Exposure Categories C or D, where the 3-second-gust basic wind speed is 110 mph (49 m/sec) or greater.

1706.2 Structural wood. Continuous special inspection is required during field gluing operations of elements of the main windforce-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of components within the main windforce-resisting system, including wood shear walls, wood diaphragms, drag struts, braces and hold-downs.

Exception: Special inspection is not required for wood shear walls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other components of the main windforce-resisting system, where the fastener spacing of the sheathing is more than 4 inches (102 mm) on center.

1706.3 Cold-formed steel light-frame construction. Periodic special inspection is required during welding operations of elements of the main windforce-resisting system. Periodic special inspection is required for screw attachment, bolting, anchoring and other fastening of components within the main windforce-resisting system, including shear walls, braces, diaphragms, collectors (drag struts) and hold-downs.

Exception: Special inspection is not required for cold-formed steel light-frame shear walls, braces, diaphragms, collectors (drag struts) and hold-downs where either of the following apply:

  1. The sheathing is gypsum board or fiberboard.
  2. The sheathing is wood structural panel or steel sheets on only one side of the shear wall, shear panel or diaphragm assembly and the fastener spacing of the sheathing is more than 4 inches (102 mm) on center (o.c.).

1706.4 Wind-resisting components. Periodic special inspection is required for the following systems and components:

  1. Roof cladding.
  2. Wall cladding.

SECTION 1707
SPECIAL INSPECTIONS FOR
SEISMIC RESISTANCE

1707.1 Special inspections for seismic resistance. Special inspections itemized in Sections 1707.2 through 1707.9, unless exempted by the exceptions of Section 1704.1, 1705.3, or 1705.3.1, are required for the following:

  1. The seismic-force-resisting systems in structures assigned to Seismic Design Category C, D, E or F, as determined in Section 1613.
  2. Designated seismic systems in structures assigned to Seismic Design Category D, E or F.
  3. Architectural, mechanical and electrical components in structures assigned to Seismic Design Category C, D, E or F that are required in Sections 1707.6 and 1707.7.

1707.2 Structural steel. Special inspection for structural steel shall be in accordance with the quality assurance plan requirements of AISC 341.

Exceptions:

  1. Special inspections of structural steel in structures assigned to Seismic Design Category C that are not specifically detailed for seismic resistance, with a response modification coefficient, R, of 3 or less, excluding cantilever column systems.
  2. For ordinary moment frames, ultrasonic and magnetic particle testing of complete joint penetration groove welds are only required for demand critical welds.

1707.3 Structural wood. Continuous special inspection is required during field gluing operations of elements of the seismic-force-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of components within the seismic-force-resisting system, including wood shear walls, wood diaphragms, drag struts, braces, shear panels and hold-downs.

Exception: Special inspection is not required for wood shear walls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other components of the seismic-force-resisting system, where the fastener spacing of the sheathing is more than 4 inches (102 mm) on center (o.c.).

1707.4 Cold-formed steel light-frame construction. Periodic special inspection is required during welding operations of elements of the seismic-force-resisting system. Periodic special inspection is required for screw attachment, bolting, anchoring and other fastening of components within the seis-

143

mic-force-resisting system, including shear walls, braces, diaphragms, collectors (drag struts) and hold-downs.

Exception: Special inspection is not required for cold-formed steel light-frame shear walls, braces, diaphragms, collectors (drag struts) and hold-downs where either of the following apply:

  1. The sheathing is gypsum board or fiberboard.
  2. The sheathing is wood structural panel or steel sheets on only one side of the shear wall, shear panel or diaphragm assembly and the fastener spacing of the sheathing is more than 4 inches (102 mm) o.c.

1707.5 Storage racks and access floors. Periodic special inspection is required during the anchorage of access floors and storage racks 8 feet (2438 mm) or greater in height in structures assigned to Seismic Design Category D, E or F.

1707.6 Architectural components. Periodic special inspection during the erection and fastening of exterior cladding, interior and exterior nonbearing walls and interior and exterior veneer in structures assigned to Seismic Design Category D, E or F.

Exceptions:

  1. Special inspection is not required for exterior cladding, interior and exterior nonbearing walls and interior and exterior veneer 30 feet (9144 mm) or less in height above grade or walking surface.
  2. Special inspection is not required for exterior cladding and interior and exterior veneer weighing 5 psf (24.5 N/m2) or less.
  3. Special inspection is not required for interior nonbearing walls weighing 15 psf (73.5 N/m2) or less.

1707.7 Mechanical and electrical components. Special inspection for mechanical and electrical equipment shall be as follows:

  1. Periodic special inspection is required during the anchorage of electrical equipment for emergency or standby power systems in structures assigned to Seismic Design Category C, D, E or F;
  2. Periodic special inspection is required during the installation of anchorage of other electrical equipment in structures assigned to Seismic Design Category E or F;
  3. Periodic special inspection is required during installation of piping systems intended to carry flammable, combustible or highly toxic contents and their associated mechanical units in structures assigned to Seismic Design Category C, D, E or F;
  4. Periodic special inspection is required during the installation of HVAC ductwork that will contain hazardous materials in structures assigned to Seismic Design Category C, D, E or F; and
  5. Periodic special inspection is required during the installation of vibration isolation systems in structures assigned to Seismic Design Category C, D, E or F where the construction documents require a nominal clearance of ¼inch (6.4 mm) or less between the equipment support frame and restraint.

1707.8 Designated seismic system verifications. The special inspector shall examine designated seismic systems requiring seismic qualification in accordance with Section 1708.4 and verify that the label, anchorage or mounting conforms to the certificate of compliance.

1707.9 Seismic isolation system. Periodic special inspection is required during the fabrication and installation of isolator units and energy dissipation devices that are part of the seismic isolation system.

SECTION 1708
STRUCTURAL TESTING FOR
SEISMIC RESISTANCE

1708.1 Testing and qualification for seismic resistance. The testing and qualification specified in Sections 1708.2 through 1708.5, unless exempted from special inspections by the exceptions of Section 1704.1, 1705.3 or 1705.3.1 are required as follows:

  1. The seismic-force-resisting systems in structures assigned to Seismic Design Category C, D, E or F, as determined in Section 1613 shall meet the requirements of Sections 1708.2 and 1708.3, as applicable.
  2. Designated seismic systems in structures assigned to Seismic Design Category C, D, E or F subject to the special certification requirements of ASCE 7 Section 13.2.2 are required to be tested in accordance with Section 1708.4.
  3. Architectural, mechanical and electrical components in structures assigned to Seismic Design Category C, D, E or F with an Ip = 1.0 are required to be tested in accordance with Section 1708.4 where the general design requirements of ASCE 7 Section 13.2.1, Item 2 for manufacturer's certification are satisfied by testing.
  4. The seismic isolation system in seismically isolated structures shall meet the testing requirements of Section 1708.5.

1708.2 Concrete reinforcement. Where reinforcement complying with ASTM A 615 is used to resist earthquake-induced flexural and axial forces in special moment frames, special structural walls and coupling beams connecting special structural walls, in structures assigned to Seismic Design Category B, C, D, E or F as determined in Section 1613, the reinforcement shall comply with Section 21.1.5.2 of ACI 318. Certified mill test reports shall be provided for each shipment of such reinforcement. Where reinforcement complying with ASTM A 615 is to be welded, chemical tests shall be performed to determine weldability in accordance with Section 3.5.2 of ACI 318.

1708.3 Structural steel. Testing for structural steel shall be in accordance with the quality assurance plan requirements of AISC 341.

Exceptions:

  1. Testing for structural steel in structures assigned to Seismic Design Category C that are not specifically detailed for seismic resistance, with a response modification coefficient, R, of 3 or less, excluding cantilever column systems.144
  2. For ordinary moment frames, ultrasonic and magnetic particle testing of complete joint penetration groove welds are only required for demand critical welds.

1708.4 Seismic certification of nonstructural components. The registered design professional shall state the applicable seismic certification requirements for nonstructural components and designated seismic systems on the construction documents.

  1. The manufacturer of each designated seismic system components subject to the provisions of ASCE 7 Section 13.2.2 shall test or analyze the component and its mounting system or anchorage and submit a certificate of compliance for review and acceptance by the registered design professional responsible for the design of the designated seismic system and for approval by the building official. Certification shall be based on an actual test on a shake table, by three-dimensional shock tests, by an analytical method using dynamic characteristics and forces, by the use of experience data (i.e., historical data demonstrating acceptable seismic performance) or by more rigorous analysis providing for equivalent safety.
  2. Manufacturer’s certification of compliance for the general design requirements of ASCE 7 Section 13.2.1 shall be based on analysis, testing or experience data.

1708.5 Seismically isolated structures. For required system tests, see Section 17.8 of ASCE 7.

SECTION 1709
CONTRACTOR RESPONSIBILITY

1709.1 Contractor responsibility. Each contractor responsible for the construction of a main wind-or seismic-force-resisting system, designated seismic system or a wind- or seismic-resisting component listed in the statement of special inspections shall submit a written statement of responsibility to the building official and the owner prior to the commencement of work on the system or component. The contractor's statement of responsibility shall contain acknowledgement of awareness of the special requirements contained in the statement of special inspection.

SECTION 1710
STRUCTURAL OBSERVATIONS

1710.1 General. Where required by the provisions of Section 1710.2 or 1710.3, the owner shall employ a registered design professional to perform structural observations as defined in Section 1702.

Prior to the commencement of observations, the structural observer shall submit to the building official a written statement identifying the frequency and extent of structural observations.

At the conclusion of the work included in the permit, the structural observer shall submit to the building official a written statement that the site visits have been made and identify any reported deficiencies which, to the best of the structural observer’s knowledge, have not been resolved.

1710.2 Structural observations for seismic resistance. Structural observations shall be provided for those structures assigned to Seismic Design Category D, E or F, as determined in Section 1613, where one or more of the following conditions exist:

  1. The structure is classified as Occupancy Category III or IV in accordance with Table 1604.5.
  2. The height of the structure is greater than 75 feet (22 860 mm) above the base.
  3. The structure is assigned to Seismic Design Category E, is classified as Occupancy Category I or II in accordance with Table 1604.5, and is greater than two stories above grade plane.
  4. When so designated by the registered design professional responsible for the structural design.
  5. When such observation is specifically required by the building official.

1710.3 Structural observations for wind requirements. Structural observations shall be provided for those structures sited where the basic wind speed exceeds 110 mph (49 m/sec) determined from Figure 1609, where one or more of the following conditions exist:

  1. The structure is classified as Occupancy Category III or IV in accordance with Table 1604.5.
  2. The building height of the structure is greater than 75 feet (22 860 mm).
  3. When so designated by the registered design professional responsible for the structural design.
  4. When such observation is specifically required by the building official.

SECTION 1711
DESIGN STRENGTHS OF MATERIALS

1711.1 Conformance to standards. The design strengths and permissible stresses of any structural material that are identified by a manufacturer’s designation as to manufacture and grade by mill tests, or the strength and stress grade is otherwise confirmed to the satisfaction of the building official, shall conform to the specifications and methods of design of accepted engineering practice or the approved rules in the absence of applicable standards.

1711.2 New materials. For materials that are not specifically provided for in this code, the design strengths and permissible stresses shall be established by tests as provided for in Section 1712.

SECTION 1712
ALTERNATIVE TEST PROCEDURE

1712.1 General. In the absence of approved rules or other approved standards, the building official shall make, or cause to

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be made, the necessary tests and investigations; or the building official shall accept duly authenticated reports from approved agencies in respect to the quality and manner of use of new materials or assemblies as provided for in Section 104.11, Chapter 1, Division II. The cost of all tests and other investigations required under the provisions of this code shall be borne by the applicant.

[BSC] In the absence of approved rules or other approved standards, the building official shall make, or cause to be made, the necessary tests and investigations; or the building official shall accept duly authenticated reports from approved agencies in respect to the quality and manner of use of new materials or assemblies as provided for in Section 1.2.2, Chapter 1, Division I. The cost of all tests and other investigations required under the provisions of this code shall be borne by the applicant.

SECTION 1713
TEST SAFE LOAD

1713.1 Where required. Where proposed construction is not capable of being designed by approved engineering analysis, or where proposed construction design method does not comply with the applicable material design standard, the system of construction or the structural unit and the connections shall be subjected to the tests prescribed in Section 1715. The building official shall accept certified reports of such tests conducted by an approved testing agency, provided that such tests meet the requirements of this code and approved procedures.

SECTION 1714
IN-SITU LOAD TESTS

1714.1 General. Whenever there is a reasonable doubt as to the stability or load-bearing capacity of a completed building, structure or portion thereof for the expected loads, an engineering assessment shall be required. The engineering assessment shall involve either a structural analysis or an in-situ load test, or both. The structural analysis shall be based on actual material properties and other as-built conditions that affect stability or load-bearing capacity, and shall be conducted in accordance with the applicable design standard. If the structural assessment determines that the load-bearing capacity is less than that required by the code, load tests shall be conducted in accordance with Section 1714.2. If the building, structure or portion thereof is found to have inadequate stability or load-bearing capacity for the expected loads, modifications to ensure structural adequacy or the removal of the inadequate construction shall be required.

1714.2 Test standards. Structural components and assemblies shall be tested in accordance with the appropriate material standards listed in Chapter 35. In the absence of a standard that contains an applicable load test procedure, the test procedure shall be developed by a registered design professional and approved. The test procedure shall simulate loads and conditions of application that the completed structure or portion thereof will be subjected to in normal use.

1714.3 In-situ load tests. In-situ load tests shall be conducted in accordance with Section 1714.3.1 or 1714.3.2 and shall be supervised by a registered design professional. The test shall simulate the applicable loading conditions specified in Chapter 16 as necessary to address the concerns regarding structural stability or the building, structure or portion thereof.

1714.3.1 Load test procedure specified. Where a standard listed in Chapter 35 contains an applicable load test procedure and acceptance criteria, the test procedure and acceptance criteria in the standard shall apply. In the absence of specific load factors or acceptance criteria, the load factors and acceptance criteria in Section 1714.3.2 Shall apply.

1714.3.2 Load test procedure not specified. In the absence of applicable load test procedures contained within a standard referenced by this code or acceptance criteria for a specific material or method of construction, such existing structure shall be subjected to a test procedure developed by a registered design professional that simulates applicable loading and deformation conditions. For components that are not a part of the seismic-load-resisting system, the test load shall be equal to two times the unfactored design loads. The test load shall be left in place for a period of 24 hours. The structure shall be considered to have successfully met the test requirements where the following criteria are satisfied:

  1. Under the design load, the deflection shall not exceed the limitations specified in Section 1604.3.
  2. Within 24 hours after removal of the test load, the structure shall have recovered not less than 75 percent of the maximum deflection.
  3. During and immediately after the test, the structure shall not show evidence of failure.

SECTION 1715
PRECONSTRUCTION LOAD TESTS

1715.1 General. In evaluating the physical properties of materials and methods of construction that are not capable of being designed by approved engineering analysis or do not comply with applicable material design standards listed in Chapter 35, the structural adequacy shall be predetermined based on the load test criteria established in this section.

1715.2 Load test procedures specified. Where specific load test procedures, load factors and acceptance criteria are included in the applicable design standards listed in Chapter 35, such test procedures, load factors and acceptance criteria shall apply. In the absence of specific test procedures, load factors or acceptance criteria, the corresponding provisions in Section 1715.3 shall apply.

1715.3 Load test procedures not specified. Where load test procedures are not specified in the applicable design standards listed in Chapter 35, the load-bearing and deformation capacity of structural components and assemblies shall be determined on the basis of a test procedure developed by a registered design professional that simulates applicable loading and deformation conditions. For components and assemblies that are not a part of the seismic-force-resisting system, the test shall be as specified in Section 1715.3.1. Load tests shall simulate the applicable loading conditions specified in Chapter 16.

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1715.3.1 Test procedure. The test assembly shall be subjected to an increasing superimposed load equal to not less than two times the superimposed design load. The test load shall be left in place for a period of 24 hours. The tested assembly shall be considered to have successfully met the test requirements if the assembly recovers not less than 75 percent of the maximum deflection within 24 hours after the removal of the test load. The test assembly shall then be reloaded and subjected to an increasing superimposed load until either structural failure occurs or the superimposed load is equal to two and one-half times the superimposed load at which the deflection limitations specified in Section 1715.3.2 were reached, or the load is equal to two and one-half times the superimposed design load. In the case of structural components and assemblies for which deflection limitations are not specified in Section 1715.3.2, the test specimen shall be subjected to an increasing superimposed load until structural failure occurs or the load is equal to two and one-half times the desired superimposed design load. The allowable superimposed design load shall be taken as the lesser of:

  1. The load at the deflection limitation given in Section 1715.3.2.
  2. The failure load divided by 2.5.
  3. The maximum load applied divided by 2.5.

1715.3.2 Deflection. The deflection of structural members under the design load shall not exceed the limitations in Section 1604.3.

1715.4 Wall and partition assemblies. Load-bearing wall and partition assemblies shall sustain the test load both with and without window framing. The test load shall include all design load components. Wall and partition assemblies shall be tested both with and without door and window framing.

1715.5 Exterior window and door assemblies. The design pressure rating of exterior windows and doors in buildings shall be determined in accordance with Section 1715.5.1 or 1715.5.2.

Exception: Structural wind load design pressures for window units smaller than the size tested in accordance with Section 1715.5.1 or 1715.5.2 shall be permitted to be higher than the design value of the tested unit provided such higher pressures are determined by accepted engineering analysis. All components of the small unit shall be the same as the tested unit. Where such calculated design pressures are used, they shall be validated by an additional test of the window unit having the highest allowable design pressure.

1715.5.1 Exterior windows and doors. Exterior windows and sliding doors shall be tested and labeled as conforming to AAMA/WDMA/CSA101/I.S.2/A440. The label shall state the name of the manufacturer, the approved labeling agency and the product designation as specified in AAMA/WDMA/CSA 101/I.S.2/A440. Exterior side-hinged doors shall be tested and labeled as conforming to AAMA/WDMA/CSA 101/I.S.2/A440 shall not be subject to the requirements of Sections 2403.2 and 2403.3.

1715.5.2 Exterior windows and door assemblies not provided for in Section 1715.5.1. Exterior window and door assemblies shall be tested in accordance with ASTM E 330. Structural performance of garage doors shall be determined in accordance with either ASTM E 330 or ANSI/DASMA 108, and shall meet the acceptance criteria of ANSI/DASMA 108. Exterior window and door assemblies containing glass shall comply with Section 2403. The design pressure for testing shall be calculated in accordance with Chapter 16. Each assembly shall be tested for 10 seconds at a load equal to 1.5 times the design pressure.

1715.6 Test specimens. Test specimens and construction shall be representative of the materials, workmanship and details normally used in practice. The properties of the materials used to construct the test assembly shall be determined on the basis of tests on samples taken from the load assembly or on representative samples of the materials used to construct the load test assembly. Required tests shall be conducted or witnessed by an approved agency.

SECTION 1716
MATERIAL AND TEST STANDARDS

1716.1 Test standards for joist hangers and connectors.

1716.1.1 Test standards for joist hangers. The vertical load-bearing capacity, torsional moment capacity and deflection characteristics of joist hangers shall be determined in accordance with ASTM D 1761 using lumber having a specific gravity of 0.49 or greater, but not greater than 0.55, as determined in accordance with AF&PA NDS for the joist and headers.

Exception: The joist length shall not be required to exceed 24 inches (610 mm).

1716.1.2 Vertical load capacity for joist hangers. The vertical load capacity for the joist hanger assemblies as specified in ASTM D 1761. If the ultimate vertical load for any one of the tests varies more than 20 percent from the average ultimate vertical load, at least three additional tests hanger shall be conducted. The allowable vertical load of the joist hanger shall be the lowest value determined from the following:

  1. The lowest ultimate vertical load for a single hanger from any test divided by three (where three tests are conducted and each ultimate vertical load does not vary more than 20 percent from the average ultimate vertical load).
  2. The average ultimate vertical load for a single hanger from all tests divided by three (where six or more tests are conducted).
  3. The average from all tests of the vertical loads that produce a vertical movement of the joist with respect to the header of 1/8 inch (3.2 mm).147
  4. The sum of the allowable design loads for nails or other fasteners utilized to secure the joist hanger to the wood members and allowable bearing loads that contribute to the capacity of the hanger.
  5. The allowable design load for the wood members forming the connection.

1716.1.3 Torsional moment capacity for joist hangers. The torsional moment capacity for the joist hanger shall be determined by testing at least three joist hanger assemblies as specified in ASTM D 1761. The allowable torsional moment of the joist hanger shall be the average torsional moment at which the lateral movement of the top or bottom of the joist with respect to the original position of the joist is 1/8 inch (3.2 mm).

1716.1.4 Design value modifications for joist hangers. Allowable design values for joist hangers that are determined by Item 4 or 5 in Section 1716.1.2 shall be permitted to be modified by the appropriate duration of loading factors as specified in AF&PA NDS but shall not exceed the direct loads as determined by Item 1, 2 or 3 in Section 1716.1.2. Allowable design values determined by Item 1, 2 or 3 in Section 1716.1.2 shall not be modified by duration of loading factors.

1716.2 Concrete and clay roof tiles.

1716.2.1 Overturning resistance. Concrete and clay roof tiles shall be tested to determine their resistance to overturning due to wind in accordance with SBCCI SSTD 11 and Chapter 15.

1716.2.2 Wind tunnel testing. When roof tiles do not satisfy the limitations in Chapter 16 for rigid tile, a wind tunnel test shall be used to determine the wind characteristics of the concrete or clay tile roof covering in accordance with SBCCI SSTD 11 and Chapter 15.

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CALIFORNIA BUILDING CODE-MATRIX ADOPTION TABLE
CHAPTER 17A – STRUCTURAL TESTS AND SPECIAL INSPECTIONS
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCECCASLSLC
121-ACACSSSS/CC1234
Adopt entire chapter      XXX  X        
Adopt entire chapter as
amended (amended sections
listed below)		                    
Adopt only those sections that
are listed below		                    
Chapter/Section                    
                     
149 150

CHAPTER 17A
STRUCTURAL TESTS AND SPECIAL INSPECTIONS

SECTION 1701A
GENERAL

1701A.1 Scope. The provisions of this chapter shall govern the quality, workmanship and requirements for materials covered. Materials of construction and tests shall conform to the applicable standards listed in this code.

1701A.1.1 Application. The scope of application of Chapter 17A is as follows:

  1. Structures regulated by the Division of the State Architect—Structural Safety, which include those applications listed in Sections 1.9.2.1 (DSA-SS), and 1.9.2.2 (DSA-SS/CC). These applications include public elementary and secondary schools, community colleges and state-owned or state-leased essential services buildings
  2. Structures regulated by the Office of Statewide Health Planning and Development (OSHPD), which include those applications listed in Sections 1.10.1 and 1.10.4. These applications include hospitals, skilled nursing facilities, intermediate care facilities and correctional treatment centers.

Exception:[OSHPD 2] Single-story Type V skilled nursing or intermediate care facilities utilizing wood-frame or light-steel-frame construction as defined in Health and Safety Code Section 129725, which shall comply with Chapter 17 and any applicable amendments therein.

1701A.1.2 Amendments in this chapter. DSA-SS and OSHPD adopt this chapter and all amendments.

Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopting agency, as follows:

  1. Division of the State Architect-Structural Safety:

    [DSA-SS] For applications listed in Section 1.9.2.1

    [DSA-SS/CC] For applications listed in Section 1.9.2.2.

  2. Office of Statewide Health Planning and Development:

    [OSHPD 1] For applications listed in Section 1.10.1.

    [OSHPD 4] For applications listed in Section 1.10.4.

1701A.1.3 Reference to other chapters.

1701A.1.3.1 [DSA-SS/CC] Where reference within this chapter is made to sections in Chapters 16A, 19A, 21A, 22A and 34A, the provisions in Chapters 16, 19, 21, 22 and 34 respectively shall apply instead.

1701A.2 New materials. New building materials, equipment, appliances, systems or methods of construction not provided for in this code, and any material of questioned suitability proposed for use in the construction of a building or structure, shall be subjected to the tests prescribed in this chapter and in the approved rules to determine character, quality and limitations of use.

1701A.3 Used materials. The use of second-hand materials that meet the minimum requirements of this code for new materials shall be permitted.

1701A.4 Special inspectors. [OSHPD 1 and 4] In addition to the inspector(s) of record required by Title 24, Part 1, Section 7-144, the owner shall employ one or more special inspectors who shall provide inspections during construction on the types of work listed under Chapters 17A, 18A, 19A, 20, 21A, 22A, 23, 25, 34A, and noted in the test, inspection and observation (TIO) program required by Sections 7-141, 7-145 and 7-149 of Title 24, part 1, of the California Administrative Code. Test, inspection and observation (TIO) program shall satisfy requirements of Section 1704A.1.1.

1701A.5 Special inspectors. [DSA-SS & DSA-SS/CC] In addition to the project inspector required by Title 24, Part 1, Section 4-333, the owner shall employ one or more special inspectors who shall provide inspections during construction on the types of work listed under Chapters 17A, 18A, 19A, 20, 21A, 22A, 23, 25, 34 and noted in the special test, inspection and observation plan required by Section 4-335 of Title 24, Part 1, of the California Administrative Code.

SECTION 1702A
DEFINITIONS

1702A.1 General. The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meanings shown herein.

APPROVED AGENCY. An established and recognized agency regularly engaged in conducting tests or furnishing inspection services, when such agency has been approved.

APPROVED FABRICATOR. An established and qualified person, firm or corporation approved by the building official pursuant to Chapter 17 of this code.

CERTIFICATE OF COMPLIANCE. A certificate stating that materials and products meet specified standards or that work was done in compliance with approved construction documents.

DESIGNATED SEISMIC SYSTEM. Those architectural, electrical and mechanical systems and their components that require design in accordance with Chapter 13 of ASCE 7 and for which the component importance factor, Ip, is greater than 1 in accordance with Section 13.1.3 of ASCE 7.

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FABRICATED ITEM. Structural, load-bearing or lateral load-resisting assemblies consisting of materials assembled prior to installation in a building or structure, or subjected to operations such as heat treatment, thermal cutting, cold working or reforming after manufacture and prior to installation in a building or structure. Materials produced in accordance with standard specifications referenced by this code, such as rolled structural steel shapes, steel-reinforcing bars, masonry units, and wood structural panels or in accordance with a standard, listed in Chapter 35, which provides requirements for quality control done under the supervision of a third-party quality control agency shall not be considered "fabricated items."

INSPECTION CERTIFICATE. An identification applied on a product by an approved agency containing the name of the manufacturer, the function and performance characteristics, and the name and identification of an approved agency that indicates that the product or material has been inspected and evaluated by an approved agency (see Section 1703A.5 and  Label,” "Manufacturer's designation" and "Mark").

INTUMESCENT FIRE-RESISTANT COATINGS. Thin film liquid mixture applied to substrates by brush, roller, spray or trowel which expands into a protective foamed layer to provide fire-resistant protection of the substrates when exposed to flame or intense heat.

MAIN WINDFORCE-RESISTING SYSTEM. An assemblage of structural elements assigned to provide support and stability for the overall structure. The system generally receives wind loading from more than one surface.

MASTIC FIRE-RESISTANT COATINGS. Liquid mixture applied to a substrate by brush, roller, spray or trowel that provides fire-resistant protection of a substrate when exposed to flame or intense heat.

PROJECT INSPECTOR [DSA-SS & DSA-SS/CC] The person approved to provide inspection in accordance with Title 24, Part 1, California Administrative Code, Section 4-333(b). The term "project inspector" is synonymous with "inspector of record."

SPECIAL INSPECTION. Inspection as herein required of the materials, installation, fabrication, erection or placement of components and connections requiring special expertise to ensure compliance with approved construction documents and referenced standards (see Section 1704A).

SPECIAL INSPECTION, CONTINUOUS. The full-time observation of work requiring special inspection by an approved special inspector who is present in the area where the work is being performed.

SPECIAL INSPECTION, PERIODIC. The part-time or intermittent observation of work requiring special inspection by an approved special inspector who is present in the area where the work has been or is being performed and at the completion of the work.

SPRAYED FIRE-RESISTANT MATERIALS. Cementitious or fibrous materials that are sprayed to provide fire-resistant protection of the substrates.

STRUCTURAL OBSERVATION. The visual observation of the structural system by a registered design professional for general conformance to the approved construction documents. Structural observation does not include or waive the responsibility for the inspection required by Section 110, 1704A or other sections of this code.

SECTION 1703A
APPROVALS

1703A.1 Approved agency. An approved agency shall provide all information as necessary for the building official to determine that the agency meets the applicable requirements.

1703A.1.1 Independence. An approved agency shall be objective, competent and independent from the contractor responsible for the work being inspected. The agency shall also disclose possible conflicts of interest so that objectivity can be confirmed.

1703A.1.2 Equipment. An approved agency shall have adequate equipment to perform required tests. The equipment shall be periodically calibrated.

1703A.1.3 Personnel. An approved agency shall employ experienced personnel educated in conducting, supervising and evaluating tests and/or inspections.

1703A.2 Written approval. Any material, appliance, equipment, system or method of construction meeting the requirements of this code shall be approved in writing after satisfactory completion of the required tests and submission of required test reports.

1703A.3 Approved record. For any material, appliance, equipment, system or method of construction that has been approved, a record of such approval, including the conditions and limitations of the approval, shall be kept on file in the building official's office and shall be open to public inspection at appropriate times.

1703A.4 Performance. Specific information consisting of test reports conducted by an approved testing agency in accordance with standards referenced in Chapter 35, or other such information as necessary, shall be provided for the building official to determine that the material meets the applicable code requirements.

1703A.4.1 Research and investigation. Sufficient technical data shall be submitted to the building official to substantiate the proposed use of any material or assembly. If it is determined that the evidence submitted is satisfactory proof of performance for the use intended, the building official shall approve the use of the material or assembly subject to the requirements of this code. The costs, reports and investigations required under these provisions shall be paid by the applicant.

1703A.4.2 Research reports. Supporting data, where necessary to assist in the approval of materials or assemblies not specifically provided for in this code, shall consist of valid research reports from approved sources.

1703A.5 Labeling. Where materials or assemblies are required by this code to be labeled, such materials and assemblies shall be labeled by an approved agency in accordance with Section 1703A. Products and materials required to be labeled shall be

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labeled in accordance with the procedures set forth in Sections 1703A.5.1 through 1703A.5.3.

1703A.5.1 Testing. An approved agency shall test a representative sample of the product or material being labeled to the relevant standard or standards. The approved agency shall maintain a record of the tests performed. The record shall provide sufficient detail to verify compliance with the test standard.

1703A.5.2 Inspection and identification. The approved agency shall periodically perform an inspection, which shall be in-plant if necessary, of the product or material that is to be labeled. The inspection shall verify that the labeled product or material is representative of the product or material tested.

1703A.5.3 Label information. The label shall contain the manufacturer's or distributor's identification, model number, serial number or definitive information describing the product or material's performance characteristics and approved agency's identification.

1703A.6 Evaluation and follow-up inspection services. Where structural components or other items regulated by this code are not visible for inspection after completion of a prefabricated assembly, the applicant shall submit a report of each prefabricated assembly. The report shall indicate the complete details of the assembly, including a description of the assembly and its components, the basis upon which the assembly is being evaluated, test results and similar information and other data as necessary for the building official to determine conformance to this code. Such a report shall be approved by the building official.

1703A.6.1 Follow-up inspection. The applicant shall provide for special inspections of fabricated items in accordance with Section 1704A.2.

1703A.6.2 Test and inspection records. Copies of necessary test and inspection records shall be filed with the building official.

SECTION 1704A
SPECIAL INSPECTIONS

1704A.1 General. Where application is made for construction as described in this section, the owner shall employ one or more approved agencies to perform inspections during construction on the types of work listed under Section 1704A. These inspections are in addition to the inspections identified in Section 110.

The special inspector shall be a qualified person who shall demonstrate competence, to the satisfaction of the building official, for the inspection of the particular type of construction or operation requiring special inspection. The registered design professional in responsible charge and engineers of record involved in the design of the project are permitted to act as the approved agency and their personnel are permitted to act as the special inspector for the work designed by them, provided those personnel meet the qualification requirements of this section to the satisfaction of the building official. The special inspector shall provide written documentation to the building official demonstrating his or her competence and relevant experience or training. Experience or training shall be considered relevant when the documented experience or training is related in complexity to the same type of special inspection activities for projects of similar complexity and material qualities. These qualifications are in addition to qualifications specified in other sections of this code.

Exceptions:

  1. Special inspections are not required for work of a minor nature or as warranted by conditions in the jurisdiction as approved by the building official.
  2. Special inspections are not required for building components unless the design involves the practice of professional engineering or architecture as defined by applicable state statutes and regulations governing the professional registration and certification of engineers or architects.
  3. Unless otherwise required by the building official, special inspections are not required for Group U occupancies that are accessory to a residential occupancy including, but not limited to, those listed in Section 312.1.

1704A.1.1 Statement of special inspections. The applicant shall submit a statement of special inspections prepared by the registered design professional in responsible charge in accordance with Section 107.1 as a condition for issuance. This statement shall be in accordance with Section 1705A.

Exception: The statement of special inspections is permitted to be prepared by a qualified person approved by the building official for construction not designed by a registered design professional.

1704A.1.2 Report requirement. The inspector of record and special inspectors shall keep records of inspections. The inspector of record and special inspector shall furnish inspection reports to the building official, and to the registered design professional in responsible charge as required by Title 24, Part 1. Reports shall indicate that work inspected was or was not completed in conformance to approved construction documents as required by Title 24, Parts 1 and 2. Discrepancies shall be brought to the immediate attention of the contractor for correction. If they are not corrected, the discrepancies shall be brought to the attention of the building official and to the registered design professional in responsible charge prior to the completion of that phase of the work. A final report documenting required special inspections and correction of any discrepancies noted in the inspections shall be submitted at a point in time agreed upon prior to the start of work by the applicant and the building official.

1704A.2 Inspection of fabricators. Where fabrication of structural load-bearing members and assemblies is being performed on the premises of a fabricator's shop, special inspection of the fabricated items shall be required by this section and as required elsewhere in this code.

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1704A.2.1 Fabrication and implementation procedures. The special inspector shall verify that the fabricator maintains detailed fabrication and quality control procedures that provide a basis for inspection control of the workmanship and the fabricator's ability to conform to approved construction documents and referenced standards. The special inspector shall review the procedures for completeness and adequacy relative to the code requirements for the fabricator's scope of work.

1704A.3 Steel construction. The special inspections for steel elements of buildings and structures shall be as required by Section 1704A.3 and Table 1704A.3.

Exceptions:

  1. Special inspection of the steel fabrication process shall not be required where the fabricator does not perform any welding, thermal cutting or heating operation of any kind as part of the fabrication process. In such cases, the fabricator shall be required to submit a detailed procedure for material control that demonstrates the fabricator's ability to maintain suitable records and procedures such that, at any time during the fabrication process, the material specification, grade and mill test reports for the main stress-carrying elements are capable of being determined.
  2. The special inspector need not be continuously present during welding of the following items, provided the materials, welding procedures and qualifications of welders are verified prior to the start of the work; periodic inspections are made of the work in progress and a visual inspection of all welds is made prior to completion or prior to shipment of shop welding.
    1. Single-pass fillet welds not exceeding 5/16 inch (7.9 mm) in size.
    2. Floor and roof deck welding.
    3. Welded studs when used for structural diaphragm.
    4. Welded sheet steel for cold-formed steel members.
    5. Welding of stairs and railing systems.

1704A.3.1 Welding. Welding inspection and welding inspector qualification shall be in accordance with this section.

1704A.3.1.1 Structural steel. Welding inspection and welding inspector qualification for structural steel shall be in accordance with AWS D1.1.

1704A.3.1.2 Cold-formed steel. Welding inspection and welding inspector qualification for cold-formed steel floor and roof decks shall be in accordance with AWS D1.3.

1704A.3.1.3 Reinforcing steel. Welding inspection and welding inspector qualification for reinforcing steel shall be in accordance with AWS D1.4 and ACI 318.

1704A.3.1.4 Inspection of Structural Welding. Inspection of all shop and field welding operations shall be made by a qualified welding inspector approved by the enforcement agency. The minimum requirements for a qualified welding inspector shall be as those for an AWS certified welding inspector (CWI), as defined in the provisions of the AWS QC1. All welding inspectors shall be as approved by the enforcement agency.

The welding inspector shall make a systematic daily record of all welds. This record shall include in addition to other required records:

  1. Identification marks of welders.
  2. List of defective welds.
  3. Manner of correction of defects.

The welding inspector shall check the material, details of construction and procedure, as well as workmanship of the welds. The inspector shall verify that the installation of end-welded stud shear connectors is in accordance with the requirements of AWS D1.1 and the approved plans and specifications. The inspector shall furnish the architect, structural engineer and the enforcement agency with a verified report that the welding is proper and has been done in conformity with AWS D1.1, D1.8 and the approved construction documents.

1704A.3.2 Details. The special inspector shall perform an inspection of the steel frame to verify compliance with the details shown on the approved construction documents, such as bracing, stiffening, member locations and proper application of joint details at each connection.

1704A.3.2.1 Steel joist and joist girder inspection. Special inspection is required during the manufacture and welding of steel joists or joist girders. The special inspector shall verify that proper quality control procedures and tests have been employed for all materials and the manufacturing process, and shall perform visual inspection of the finished product. The special inspector shall place a distinguishing mark, and/or tag with this distinguishing mark, on each inspected joist or joist girder. This mark or tag shall remain on the joist or joist girder throughout the job-site receiving and erection process.

1704A.3.2.2 Light-framed steel truss inspection. The manufacture of cold-formed light-framed steel trusses shall be continuously inspected by a qualified special inspector approved by the enforcement agency. The special inspector shall verify conformance of materials and manufacture with approved plans and specifications. The special inspector shall place a distinguishing mark, and/or tag with this distinguishing mark, on each inspected truss. This mark or tag shall remain on the truss throughout the job-site receiving and erection process.

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TABLE 1704A.3
REQUIRED VERIFICATION AND INSPECTION OF STEEL CONSTRUCTION
VERIFICATION AND INSPECTIONCONTINUOUSPERIODICREFERENCED STANDARDaCBC REFERENCE
For SI: 1 inch =25.4 mm.
a. Where applicable, see also Section 1707A.1, Special inspection for seismic resistance.
1. Material verification of high-strength bolts, nuts and washers:
a. Identification markings to conform to ASTM standards specified in the approved construction documents.—XAISC 360, Section A3.3 and applicable ASTM material standards—
b. Manufacturer's certificate of compliance required—X——
2. Inspection of high-strength bolting:
a. Snug-tight joints.—XAISC 360, Section M2.51704A.3.3
b. Pretensioned and slip-critical joints using turn-of-nut with matchmarking, twist-off bolt or direct tension indicator methods of installation.—X
c. Pretensioned and slip-critical joints using turn-of-nut without matchmarking or calibrated wrench methods of installation.X—
3. Material verification of structural steel and cold-formed steel deck:
a. For structural steel, identification markings to conform to AISC 360.—XAISC 360, Section M5.5 
b. For other steel, identification markings to conform to ASTM standards specified in the approved construction documents.—XApplicable ASTM material standards
c. Manufacturer's certified test reports.—X——
4. Material verification of weld filler materials:
a. Identification markings to conform to AWS specification in the approved construction documents.—XAISC 360, Section A3.5 and applicable AWS A5 documents—
b. Manufacturer's certificate of compliance required.—X——
5. Inspection of welding:
a. Structural steel and cold-formed steel deck:
1) Complete and partial joint penetration groove welds.X—AWS D1.11704A.3.1
2) Multipass fillet welds.X—
3) Single-pass fillet welds >5/16"X—
4) Plug and slot welds.X—
5)Single-pass fillet welds ≤5/16"—X
6)Floor and roof deck welds.—XAWS D1.3  155
b.Reinforcing steel:   —
1) Verification of weldability of reinforcing steel other than ASTM A 706.—XAWS D1.4 ACI 318: Section 3.5.2
2) Reinforcing steel resisting flexural and axial forces in intermediate and special moment frames, and boundary elements of special structural walls of concrete and shear reinforcement.X—
3) Shear reinforcement.X—
4) Other reinforcing steel.—X
6. Inspection of steel frame joint details for compliance:
a. Details such as bracing and stiffening.—X—1704A.3.2
b. Member locations.—X
c. Application of joint details at each connection.—X

1704A.3.3 High-strength bolts. Installation of highstrength bolts shall be inspected in accordance with AISC 360.

1704A.3.3.1 General. While the work is in progress, the special inspector shall determine that the requirements for bolts, nuts, washers and paint; bolted parts and installation and tightening in such standards are met. For bolts requiring pretensioning, the special inspector shall observe the preinstallation testing and calibration procedures when such procedures are required by the installation method or by project plans or specifications; determine that all plies of connected materials have been drawn together and properly snugged and monitor the installation of bolts to verify that the selected procedure for installation is properly used to tighten bolts. For joints required to be tightened only to the snug-tight condition, the special inspector need only verify that the connected materials have been drawn together and properly snugged.

1704A.3.3.2 Periodic monitoring. Monitoring of bolt installation for pretensioning is permitted to be performed on a periodic basis when using the turn-of-nut method with matchmarking techniques, the direct tension indicator method or the alternate design fastener (twist-off bolt) method. Joints designated as snug tight need be inspected only on a periodic basis.

1704A.3.3.3 Continuous monitoring. Monitoring of bolt installation for pretensioning using the calibrated wrench method or the turn-of-nut method without matchmarking shall be performed on a continuous basis.

1704A.3.4 Cold-formed steel trusses spanning 60 feet or greater. Where a cold-formed steel truss clear span is 60 feet (18 288 mm) or greater, the special inspector shall verify that the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing are installed in accordance with the approved truss submittal package.

1704A.4 Concrete construction. The special inspections and verifications for concrete construction shall be as required by this section and Table 1704A.4.

Exceptions: [DSA-SS & DSA-SS/CC] Special inspections shall not be required for:

  1. Nonstructural concrete slabs supported directly on the ground, including prestressed slabs on grade, where the effective prestress in the concrete is less than 150 psi (1.03 MPa).

  2. Concrete patios, driveways and sidewalks, on grade.

1704A.4.1 Materials. In the absence of sufficient data or documentation providing evidence of conformance to quality standards for materials in Chapter 3 of ACI 318, the building official shall require testing of materials in accordance with the appropriate standards and criteria for the material in Chapter 3 of ACI 318. Weldability of reinforcement, except that which conforms to ASTM A 706, shall be determined in accordance with the requirements of Section 3.5.2 of ACI 318.

1704A.4.2 Batch plant inspection. Except as provided under Section 1704A.4.3, the quality and quantity of materials used in transit-mixed concrete and in batched aggregates shall be continuously inspected at the location

156

where materials are measured by an approved special inspector.

1704A.4.3 Waiver of continuous batch plant inspection. Continuous batch plant inspection may be waived by the registered design professional in responsible charge, subject to approval by the enforcement agency, under either of the following conditions:

  1. The concrete plant complies fully with the requirements of ASTM C 94, Sections 8 and 9, and has a current certificate from the National Ready Mixed Concrete Association or another agency acceptable to the enforcement agency. The certification shall indicate that the plant has automatic batching and recording capabilities.
  2. For single-story light framed buildings and isolated foundations supporting equipment only, where the specified compressive strength f'c of the concrete delivered to the jobsite is 3,500 psi (24.13 MPa) and where the f'c used in design is not greater than 3,000 psi (20.68 MPa).

When continuous batch plant inspection is waived, the following requirements shall apply and shall be described in the construction documents:

  1. Qualified technician of the testing laboratory shall check the first batch at the start of the day.
TABLE 1704A.4
REQUIRED VERIFICATION AND INSPECTION OF CONCRETE CONSTRUCTION
VERIFICATION AND INSPECTIONCONTINUOUSPERIODICREFERENCED STANDARDaCBC REFERENCE
For SI: 1 inch = 25.4 mm.
a. Where applicable, see also Section 1707A.1, Special inspection for seismic resistance.
1. Inspection of reinforcing steel, including prestressing tendons, and placement.—XACI 318: 3.5, 7.1–7.71913A.4
2. Inspection of reinforcing steel welding in accordance with Table 1704A.3, Item 5b.——AWS D1.4 ACI 318: 3.5.2—
3. Inspection of bolts to be installed in concrete prior to and during placement of concrete where allowable loads have been increased or where strength design is used.X—ACI 318: 8.1.3, 21.2.81911A.5, 1912A.1
4. Inspection of anchors installed in hardened concrete.—XACI 318: 3.8.6, 8.1.3, 21.2.81912A.1
5. Verifying use of required design mix,—XACI 318: Ch. 4, 5.2–5.41904A.2.2, 1913A.2, 1913A.3
6. At the time fresh concrete is sampled to fabricate specimens for strength tests, perform slump and air content tests, and determine the temperature of the concrete.X—ASTM C 172 ASTM C 31 ACI 318: 5.6, 5.81913A.10
7. Inspection of concrete and shotcrete placement for proper application techniques.X—ACI 318: 5.9, 5.101913A.6, 1913A.7, 1913A.8
8. Inspection for maintenance of specified curing temperature and techniques.—XACI 318: 5.11–5.131913A.9
9. Inspection of prestressed concrete:
  1. Application of prestressing forces.
  2. Grouting of bonded prestressing tendons in the seismic-force-resisting system.
  X X    —  ACI 318: 18.20 ACI 318: 18.18.4  —  
10. Erection of precast concrete members.—XACI 318: Ch. 16—
11. Verification of in-situ concrete strength, prior to stressing of tendons in posttensioned concrete and prior to removal of shores and forms from beams and structural slabs.—XACI 318: 6.2—
12. Inspect formwork for shape, location and dimensions of the concrete member being formed.—XACI 318: 6.1.1—
  1. Licensed weighmaster to positively identify materials as to quantity and certify to each load by a batch ticket.157
  2. Batch tickets, including actual material quantities and weights shall accompany the load and shall be transmitted to the inspector of record by a truck driver with load identified thereon. The load shall not be placed without a batch ticket identifying the mix. The inspector will keep a daily record of placements, identifying each truck, its load, time of receipt and approximate location of deposit in the structure and will transmit a copy of the daily record to the enforcement agency.

1704A.4.4 Inspection of prestressed concrete.

  1. In addition to the general inspection required for concrete work, all plant fabrication of prestressed concrete members or tensioning of posttensioned members constructed at the site shall be continuously inspected by an inspector specially approved for this purpose by the enforcement agency.
  2. The prestressed concrete plant fabrication inspector shall check the materials, equipment, tensioning procedure and construction of the prestressed members and prepare daily written reports. The inspector shall make a verified report identifying the members by mark and shall include such pertinent data as lot numbers of tendons used, tendon jacking forces, age and strength of concrete at time of tendon release and such other information that may be required.
  3. The inspector of prestressed members posttensioned at the site shall check the condition of the prestressing tendons, anchorage assemblies and concrete in the area of the anchorage, the tensioning equipment and the tensioning procedure, and prepare daily written reports. The inspector shall make a verified report of the prestressing operation identifying the members or tendons by mark and including such pertinent data as the initial cable slack, net elongation of tendons, jacking force developed, and such other information as may be required.
  4. The verified reports of construction shall show that of the inspector's own personal knowledge, the work covered by the report has been performed and materials used and installed in every material respect in compliance with the duly approved plans and specifications for plant fabrication inspection. The verified report shall be accompanied by test reports required for materials used. For site posttensioning inspections the verified report shall be accompanied by copies of calibration charts, certified by an approved testing laboratory, showing the relationship between gage readings and force applied by the jacks used in the prestressing procedure

1704A.4.5 Concrete preplacement inspection. Concrete shall not be placed until the forms and reinforcement have been inspected, all preparations for the placement have been completed, and the preparations have been checked by the inspector of record.

1704A.4.6 Placing record. A record shall be kept on the site of the time and date of placing the concrete in each portion of the structure. Such record shall be kept until the completion of the structure and shall be open to the inspection of the enforcement agency.

1704A.5 Masonry construction. Masonry construction shall be inspected and verified in accordance with the requirements of Sections 1704A.5.1 through 1704A.5.3, depending on the occupancy category of the building or structure.

1704A.5.1 Glass unit masonry and masonry veneer in Occupancy Category IV. The minimum special inspection program for glass unit masonry or masonry veneer designed by Chapter 21A or 14, or by Chapter 6 of TMS 402/ACI 530/ASCE 5, in structures classified as Occupancy Category IV, in accordance with Section 1604A.5, shall comply with Table 1704A.5.1.

1704A.5.2 Engineered masonry in Occupancy Category I. The minimum special inspection program for masonry designed by Section 2107A or 2108A or by chapters other than Chapter 5, 6 or 7 of TMS 402/ACI 530/ASCE 5 in structures classified as Occupancy Category I, in accordance with Section 1604A.5, shall comply with Table 1704A.5.1.

1704A.5.3 Engineered masonry in Occupancy Category II, III or IV. The minimum special inspection program for masonry designed by Section 2107A or 2108A or by chapters other than Chapter 6 of TMS 402/ACI 530/ASCE 5 in structures classified as Occupancy Category II, III, or IV, in accordance with Section 1604A.5, shall comply with Table 1704A.5.3.

1704A.6 Wood construction. Special inspections of the fabrication process of prefabricated wood structural elements and assemblies shall be in accordance with Section 1704A.2. Special inspections of site-built assemblies shall be in accordance with this section.

1704A.6.1 High-load diaphragms. High-load diaphragms designed in accordance with Table 2306.2.1(2) shall be installed with special inspections as indicated in Section 1704A.1. The special inspector shall inspect the wood structural panel sheathing to ascertain whether it is of the grade and thickness shown on the approved building plans. Additionally, the special inspector must verify the nominal size of framing members at adjoining panel edges, the nail or staple diameter and length, the number of fastener lines and that the spacing between fasteners in each line and at edge margins agrees with the approved building plans.

1704A.6.2 Metal-plate-connected wood trusses spanning 60 feet or greater. Where a truss clear span is 60 feet (18 288 mm) or greater, the special inspector shall verify that the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing are installed in accordance with the approved truss submittal package.

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1704A.6.3 Wood structural elements and assemblies. Special inspection of wood structural elements and assemblies is required, as specified in this section, to ensure conformance with approved drawings and specifications and applicable standards.

The special inspector shall furnish a verified report to the design professional in general responsible charge of construction observation, the structural engineer and the enforcement agency, in accordance with Title 24, Part 1 and this chapter. The verified report shall list all inspected members or trusses, and shall indicate whether or not the inspected members or trusses conform with applicable standards and the approved drawings and specifications. Any nonconforming items shall be indicated on the verified report.

1704A.6.3.1 Structural glued-laminated timber. Manufacture of all structural glued-laminated timber shall be continuously inspected by a qualified special inspector approved by the enforcement agency.

The special inspector shall verify that proper quality control procedures and tests have been employed for all materials and the manufacturing process, and shall perform visual inspection of the finished product. Each inspected member shall be stamped by the special inspector with an identification mark.

Exception: Special inspection is not required for noncustom members of 5⁄18 inch (130 mm) maximum width and 18 inch (457 mm) maximum depth, and with a maximum clear span of 32 feet (9754 mm), manufactured and marked in accordance with ANSI/AITC A 190.1 Section 6.1.1 for noncustom members.

1704A.6.3.2 Manufactured open web trusses. The manufacture of open web trusses shall be continuously inspected by a qualified special inspector approved by the enforcement agency.

The special inspector shall verify that proper quality control procedures and tests have been employed for all materials and the manufacturing process, and shall perform visual inspection of the finished product. Each inspected truss shall be stamped with an identification mark by the special inspector.

1704A.6.4 Timber connectors. The installation of all split ring and shear plate timber connectors, and timber rivets shall be continuously inspected by a qualified inspector approved by the enforcement agency. The inspector shall furnish the architect, structural engineer and the enforcement agency with a report duly verified by him that the materials timber connectors and workmanship conform to the approved plans and specifications.

1704A.7 Soils. Special inspections for existing site soil conditions, fill placement and load-bearing requirements shall be as required by this section and Table 1704A.7. The approved geotechnical report, and the construction documents prepared by the registered design professionals shall be used to determine compliance. During fill placement, the special inspector shall determine that proper materials and procedures are used in accordance with the provisions of the approved geotechnical report.

Exception: Where Section 1803 does not require reporting of materials and procedures for fill placement, the special inspector shall verify that the in-place dry density of the compacted fill is not less than 90 percent of the maximum dry density at optimum moisture content determined in accordance with ASTM D 1557.

1704A.7.1 Soil fill. All fills used to support the foundations of any building or structure shall be continuously inspected by the geotechnical engineer or his or her qualified representative. It shall be the responsibility of the geotechnical engineer to verify that fills meet the requirements of the specifications and to coordinate all fill inspection and testing during the construction involving such fills.

The duties of the geotechnical engineer or his or her qualified representative shall include, but need not be limited to, the observation of cleared areas and benches prepared to receive fill; observation of the removal of all unsuitable soils and other materials; the approval of soils to be used as fill material; the inspection of placement and compaction of fill materials; the testing of the fills; and the inspection or review of geotechnical drainage devices where required by the soils investigation, buttress fills or other similar protective measures.

A verified report shall be submitted to the enforcement agency by the geotechnical engineer. The report shall indicate that all the tests required by the construction documents were completed and that the tested materials were in compliance with the construction documents.

1704A.8 Driven deep foundations. Special inspections shall be performed during installation and testing of driven deep foundation elements as required by Table 1704A.8. The approved geotechnical report, and the construction documents prepared by the registered design professionals, shall be used to determine compliance.

1704A.8.1 Driven deep foundations observation. The installation of driven deep foundations shall be continuously observed by a qualified representative of the geotechnical engineer responsible for that portion of the project.

The representative of the geotechnical engineer shall make a report of the deep foundation-driving operation giving such pertinent data as the physical characteristics of the deep foundation-driving equipment, identifying marks for each deep foundation, the total depth of embedment for each deep foundation; and when the allowable deep foundation loads are determined by a dynamic load formula, the design formula used, and the permanent penetration under the last 10 blows. One copy of the report shall be sent to the enforcement agency.

1704A.9 Cast-in-place deep foundations. Special inspections shall be performed during installation and testing of cast-in-place deep foundation elements as required by Table 1704A.9. The approved geotechnical report, and the construction documents prepared by the registered design professionals, shall be used to determine compliance.

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TABLE 1704A.5.1
LEVEL 1 REQUIRED VERIFICATION AND INSPECTION OF MASONRY CONSTRUCTION
VERIFICATION AND INSPECTIONFREQUENCY OF INSPECTIONREFERENCE FOR CRITERIA
CONTINUOUSPERIODICCBC SECTIONTMS 402/ACI 530/ASCE 5aTMS 602/ACI 530.1/ASCE 6a
For SI: °C = [(°F) - 32]/1.8. a. The specific standards referenced are those listed in Chapter 35.
1. Compliance with required inspection provisions of the construction documents and the approved submittals shall be verified.  —   X    —    —    Art. 1.5  
2. Verification of fm and fAAC prior to construction except where specifically exempted by this code.  —    X    —    —    Art. 1.4B  
3. Verification of slump flow and VSI as delivered to the site for self-consolidating grout.  X    —    —    —    Art. 1.5B.1.b.3  
4. As masonry construction begins, the following shall be verified to ensure compliance:
a. Proportions of site-prepared mortar.—X——Art. 2.6A
b. Construction of mortar joints.—X——Art. 3.3B
c. Location of reinforcement, connectors, prestressing tendons and anchorages.—X——Art. 3.4, 3.6A
d. Prestressing technique.—X——Art. 3.6B
e. Grade and size of prestressing tendons and anchorages.—X——Art. 2.4B, 2.4H
5. During construction the inspection program shall verify:
a. Size and location of structural elements.—X——Art 3.3F
b. Type, size and location of anchors, including other details of anchorage of masonry to structural members, frames or other construction.    —        X        —      Sec. 1.2.2(e), 1.16.1      —    
c. Specified size, grade and type of reinforcement, anchor bolts, prestressing tendons and anchorages.    —        X        —        Sec. 1.15        Art. 2.4, 3.4    
d. Welding of reinforcing bars.X——Sec. 2.1.9.7.2, 3.3.3.4(b)—
e. Preparation, construction and protection of masonry during cold weather (temperature below 40°F) or hot weather (temperature above 90°F).    —        X        Sec. 2104A.3, 2104A.4        —        Art. 1.8C, 1.8D    
f. Application and measurement of prestressing force.X———Art. 3.6B 160
6. Prior to grouting, the following shall be verified to ensure compliance:
a. Grout space is clean.—X——Art. 3.2D
b. Placement of reinforcement and connectors, and prestressing tendons and anchorages.—X—Sec.1.13Art. 3.4
c. Proportions of site-prepared grout and prestressing grout for bonded tendons.—X——Art. 2.6B
d. Construction of mortar joints.—X——Art. 3.3B
7. Grout placement shall be verified to ensure compliance:X———Art. 3.5
a. Grouting of prestressing bonded tendons.X———Art. 3.6C
8. Preparation of any required grout specimens, mortar specimens and/or prisms shall be observed.—XSec. 2105A.2.2, 2105A.3—Art. 1.4
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TABLE 1704A.5.3
LEVEL 2 REQUIRED VERIFICATION AND INSPECTION OF MASONRY CONSTRUCTION
VERIFICATION AND INSPECTIONCONTINUOUSPERIODICREFERENCE FOR CRITERIA
CBC SECTIONTMS 402/ACI 530/ASCE 5aTMS 602/ACI 530.1/ASCE 6a
For SI: °C=[(°F) - 32]/1.8, 1 square foot =0.0929 m2.
a. The specific standards referenced are those listed in Chapter 35.
1. Compliance with required inspection provisions of the construction documents and the approved submittals.—X——Art. 1.5
2. Verification of fm and fAACprior to construction and for every 5,000 square feet during construction.—X——Art. 1.4B
3. Verification of proportions of materials in premixed or preblended mortar and grout as delivered to the site.—X——Art. 1.5B
4. Verification of slump flow and VSI as deliv-ered to the site for self-consolidating grout.X———Art. 1.5B.1.b.3
5. The following shall be verified to ensure compliance:
a. Proportions of site-prepared mortar, grout and prestressing grout for bonded tendons.—X——Art. 2.6A
b. Placement of masonry units and construction of mortar joints.—X——Art. 3.3B
c. Placement of reinforcement, connectors and prestressing tendons and anchorages.—X—Sec.1.15Art. 3.4, 3.6A
d. Grout space prior to grout.X———Art. 3.2D
e. Placement of grout.X———Art. 3.5
f. Placement of prestressing grout.X———Art. 3.6C
g. Size and location of structural elements.—X——Art. 3.3F
h. Type, size and location of anchors, including other details of anchorage of masonry to structural members, frames or other construction.X——Sec.1.2.2(e), 1.16.1—
i. Specified size, grade and type of reinforcement, anchor bolts, prestressing tendons and anchorages.—X—Sec. 1.15Art. 2.4, 3.4
j. Welding of reinforcing bars.X——Sec.2.1.9.7.2, 3.3.3.4 (b)—
k. Preparation, construction and protection of masonry during cold weather (temperature below 40°F) or hot weather (temperature above 90°F).—XSec.2104A.3, 2104A.4—Art. 1.8C, 1.8D
l. Application and measurement of prestressing force.X———Art. 3.6B
6. Preparation of any required grout specimens and/or prisms shall be observed.X—Sec. 2105A.2.2, 2105A.3—Art. 1.4
7. Post-Installed anchorsX—1615A.1.14 [DSA-SS & OSHPD]1615.1.12 [DSA-SS/CC]——
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TABLE 1704A.7
REQUIRED VERIFICATION AND INSPECTION OF SOILS
VERIFICATION AND INSPECTION TASKCONTINUOUS DURING TASK LISTEDPERIODICALLY DURING TASK LISTED
1. Verify materials below shallow foundations are adequate to achieve the design bearing capacity.—X
2. Verify excavations are extended to proper depth and have reached proper material.—X
3. Perform classification and testing of compacted fill materials.—X
4. Verify use of proper materials, densities and lift thicknesses during placement and compaction of compacted fill.X—
5. Prior to placement of compacted fill, observe subgrade and verify that site has been prepared properly.—X
TABLE 1704A.8
REQUIRED VERIFICATION AND INSPECTION OF DRIVEN DEEP FOUNDATION ELEMENTS
VERIFICATION AND INSPECTION TASKCONTINUOUS DURING TASK LISTEDPERIODICALLY DURING TASK LISTED
1. Verify element materials, sizes and lengths comply with the requirements.X—
2. Determine capacities of test elements and conduct additional load tests, as required.X—
3. Observe driving operations and maintain complete and accurate records for each element.X—
4. Verify placement locations and plumbness, confirm type and size of hammer, record number of blows per foot of penetration, determine required penetrations to achieve design capacity, record tip and butt elevations and document any damage to foundation element.X—
5. For steel elements, perform additional inspections in accordance with Section 1704A.3.——
6. For concrete elements and concrete-filled elements, perform additional inspections in accordance with Section 1704A.4.——
7. For specialty elements, perform additional inspections as determined by the registered design professional in responsible charge.——
TABLE 1704A.9
REQUIRED VERIFICATION AND INSPECTION OF CAST-IN-PLACE DEEP FOUNDATION ELEMENTS
VERIFICATION AND INSPECTION TASKCONTINUOUS DURING TASK LISTEDPERIODICALLY DURING TASK LISTED
1. Observe drilling operations and maintain complete and accurate records for each element.X—
2. Verify placement locations and plumbness, confirm element diameters, bell diameters (if applicable), lengths, embedment into bedrock (if applicable) and adequate end-bearing strata capacity. Record concrete or grout volumes.X—
3. For concrete elements, perform additional inspections in accordance with Section 1704A.4.——
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1704A.10 Helical pile foundations. Special inspections shall be performed continuously during installation of helical pile foundations. The information recorded shall include installation equipment used, pile dimensions, tip elevations, final depth, final installation torque and other pertinent installation data as required by the registered design professional in responsible charge. The approved geotechnical report and the construction documents prepared by the registered design professional shall be used to determine compliance.

1704A.11 Vertical masonry foundation elements.Special inspection shall be performed in accordance with Section 1704A.5 for vertical masonry foundation elements.

1704A.12 Sprayed fire-resistant materials. Special inspections for sprayed fire-resistant materials applied to floor, roof and wall assemblies and structural members shall be in accordance with Sections 1704A.12.1 through 1704A.12.6. Special inspections shall be based on the fire-resistance design as designated in the approved construction documents. The tests set forth in this section shall be based on samplings from specific floor, roof and wall assemblies and structural members. Special inspections shall be performed after the rough installation of electrical, automatic sprinkler, mechanical and plumbing systems and suspension systems for ceilings, where applicable.

1704A.12.1 Physical and visual tests. The special inspections shall include the following tests and observations to demonstrate compliance with the listing and the fire-resistance rating:

  1. Condition of substrates.
  2. Thickness of application.
  3. Density in pounds per cubic foot (kg/m3).
  4. Bond strength adhesion/cohesion.
  5. Condition of finished application.

1704A.12.2 Structural member surface conditions. The surfaces shall be prepared in accordance with the approved fire-resistance design and the written instructions of approved manufacturers. The prepared surface of structural members to be sprayed shall be inspected before the application of the sprayed fire-resistant material.

1704A.12.3 Application. The substrate shall have a minimum ambient temperature before and after application as specified in the written instructions of approved manufacturers. The area for application shall be ventilated during and after application as required by the written instructions of approved manufacturers.

1704A.12.4 Thickness. No more than 10 percent of the thickness measurements of the sprayed fire-resistant materials applied to floor, roof and wall assemblies and structural members shall be less than the thickness required by the approved fire-resistance design, but in no case less than the minimum allowable thickness required by Section 1704A.12.4.1.

1704A.12.4.1 Minimum allowable thickness. For design thicknesses 1 inch (25 mm) or greater, the minimum allowable individual thickness shall be the design thickness minus ¼ inch (6.4 mm). For design thicknesses less than 1 inch (25 mm), the minimum allowable individual thickness shall be the design thickness minus 25 percent. Thickness shall be determined in accordance with ASTM E 605. Samples of the sprayed fire-resistant materials shall be selected in accordance with Sections 1704A.12.4.2 and 1704A.12.4.3.

1704A.12.4.2 Floor, roof and wall assemblies. The thickness of the sprayed fire-resistant material applied to floor, roof and wall assemblies shall be determined in accordance with ASTM E 605, making not less than four measurements for each 1,000 square feet (93 m2) of the sprayed area in each story or portion thereof.

1704A.12.4.2.1 Cellular decks. Thickness measurements shall be selected from a square area, 12 inches by 12 inches (305 mm by 305 mm) in size. A minimum of four measurements shall be made, located symmetrically within the square area.

1704A.12.4.2.2 Fluted decks. Thickness measurements shall be selected from a square area, 12 inches by 12 inches (305 mm by 305 mm) in size. A minimum of four measurements shall be made, located symmetrically within the square area, including one each of the following: valley, crest and sides. The average of the measurements shall be reported.

1704A.12.4.3 Structural members. The thickness of the sprayed fire-resistant material applied to structural members shall be determined in accordance with ASTM E 605. Thickness testing shall be performed on not less than 25 percent of the structural members on each floor.

1704A.12.4.3.1 Beams and girders. At beams and girders thickness measurements shall be made at nine locations around the beam or girder at each end of a 12-inch (305 mm) length.

1704A.12.4.3.2 Joists and trusses. At joists and trusses, thickness measurements shall be made at seven locations around the joist or truss at each end of a 12-inch (305 mm) length.

1704A.12.4.3.3 Wide-flanged columns. At wideflanged columns, thickness measurements shall be made at 12 locations around the column at each end of a 12-inch (305 mm) length.

1704A.12.4.3.4 Hollow structural section and pipe columns. At hollow structural section and pipe columns, thickness measurements shall be made at a minimum of four locations around the column at each end of a 12-inch (305 mm) length.

1704A.12.5 Density. The density of the sprayed fire-resistant material shall not be less than the density specified in the approved fire-resistance design. Density of the sprayed fire-resistance design. Density of the sprayed fire-resistant material shall be determined in accordance with ASTM E 605. The test samples for determining the density of the sprayed fire-resistant materials shall be selected as follows:

  1. From each floor, roof and wall assembly at the rate of not less than one sample for every 2,500 square feet (232 m2) or portion thereof of the sprayed area in each story.164
  2. From beams, girders, trusses and columns at the rate of not less than one sample for each type of structural member for each 2,500 square feet (232 m2) of floor area or portion thereof in each story.

1704A.12.6 Bond strength. The cohesive/adhesive bond strength of the cured sprayed fire-resistant material applied to floor, roof and wall assemblies and structural members shall not be less than 150 pounds per square foot (psf) (7.18 kN/m2). The cohesive/adhesive bond strength shall be determined in accordance with the field test specified in ASTME 736 by testing in-place samples of the sprayed fire-resistant material selected in accordance with Sections 1704.12.6.1 through 1704.12.6.3.

1704A.12.6.1 Floor, roof and wall assemblies. The test samples for determining the cohesive/adhesive bond strength of the sprayed fire-resistant materials shall be selected from each floor, roof and wall assembly at the rate of not less than one sample for every 2,500 square feet (232 m2) of the sprayed area in each story or portion thereof.

1704A.12.6.2 Structural members. The test samples for determining the cohesive/adhesive bond strength of the sprayed fire-resistant materials shall be selected from beams, girders, trusses, columns and other structural members at the rate of not less than one sample for each type of structural member for each 2,500 square feet (232 m2) of floor area or portion thereof in each story.

1704A.12.6.3 Primer, paint and encapsulant bond tests. Bond tests to qualify a primer, paint or encapsulant shall be conducted when the sprayed fire-resistant material is applied to a primed, painted or encapsulated surface for which acceptable bond-strength performance between these coatings and the fire-resistant material has not been determined. A bonding agent approved by the SFRM manufacturer shall be applied to a primed, painted or encapsulated surface where the bond strengths are found to be less than required values.

1704A.13 Mastic and intumescent fire-resistant coatings. Special inspections for mastic and intumescent fire-resistant coatings applied to structural elements and decks shall be in accordance with AWCI 12-B. Special inspections shall be based on the fire-resistance design as designated in the approved construction documents.

1704A.14 Exterior insulation and finish systems (EIFS).Special inspections shall be required for all EIFS applications.

Exceptions:

  1. Special inspections shall not be required for EIFS applications installed over a water-resistive barrier with a means of draining moisture to the exterior.
  2. Special inspections shall not be required for EIFS applications installed over masonry or concrete walls.

1704A.14.1 Water-resistive barrier coating. A waterresistive barrier coating complying with ASTM E 2570 requires special inspection of the water-resistive barrier coating when installed over a sheathing substrate.

1704A.15 Special cases.Special inspections shall be required for proposed work that is, in the opinion of the building official, unusual in its nature, such as, but not limited to, the following examples:

  1. Construction materials and systems that are alternatives to materials and systems prescribed by this code.
  2. Unusual design applications of materials described in this code.
  3. Materials and systems required to be installed in accordance with additional manufacturer's instructions that prescribe requirements not contained in this code or in standards referenced by this code.

[F] 1704A.16 Special inspection for smoke control. Smoke control systems shall be tested by a special inspector.

[F] 1704A.16.1 Testing scope. The test scope shall be as follows:

  1. During erection of ductwork and prior to concealment for the purposes of leakage testing and recording of device location.
  2. Prior to occupancy and after sufficient completion for the purposes of pressure difference testing, flow measurements and detection and control verification.

[F] 1704A.16.2 Qualifications. Special inspection agencies for smoke control shall have expertise in fire protection engineering, mechanical engineering and certification as air balancers.

1704A.17 Shotcrete. All shotcrete work shall be continuously inspected by an inspector specially approved for that purpose by the enforcement agency. The special shotcrete inspector shall check the materials, placing equipment, details of construction and construction procedure. The inspector shall furnish a verified report that of his or her own personal knowledge the work covered by the report has been performed and materials used and installed in every material respect in compliance with the duly approved plans and specifications.

1704A.17.1 Visual examination for structural soundness of in-place shotcrete. Completed shotcrete work shall be checked visually for reinforcing bar embedment, voids, rock pockets, sand streaks and similar deficiencies by examining a minimum of three 3-inch (76 mm) cores taken from three areas chosen by the design engineer which represent the worst congestion of reinforcing bars occurring in the project. Extra reinforcing bars may be added to noncongested areas and cores may be taken from these areas. The cores shall be examined by the special inspector and a report submitted to the enforcement agency prior to final approval of the shotcrete.

Exception: Shotcrete work fully supported on earth, minor repairs and when, in the opinion of the enforcement agency, no special hazard exists.

SECTION 1705A
STATEMENT OF SPECIAL INSPECTIONS

1705A.1 General. Where special inspection or testing is required by Section 1704A, 1707A or 1708A, the registered

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design professional in responsible charge shall prepare a statement of special inspections in accordance with Section 1705A for submittal by the applicant (see Section 1704A.1.1).

1705A.2 Content of statement of special inspections. The statement of special inspections shall identify the following:

  1. The materials, systems, components and work required to have special inspection or testing by the building official or by the registered design professional responsible for each portion of the work.
  2. The type and extent of each special inspection.
  3. The type and extent of each test.
  4. Additional requirements for special inspection or testing for seismic or wind resistance as specified in Section 1705A.3, 1705A.4, 1707A or 1708A.
  5. For each type of special inspection, identification as to whether it will be continuous special inspection or periodic special inspection.

1705A.3 Seismic resistance. The statement of special inspections shall include seismic requirements for cases covered in Sections 1705A.3.1 through 1705A.3.5.

1705A.3.1 Seismic-force-resisting systems. The seismic-force-resisting systems in structures assigned to Seismic Design Category C, D, E or F, in accordance with Section 1613.

Exception: Requirements for the seismic-force-resisting system are permitted to be excluded from the statement of special inspections for steel systems in structures assigned to Seismic Design Category C that are not specifically detailed for seismic resistance, with a response modification coefficient, R, of 3 or less, excluding cantilever column systems.

1705A.3.2 Designated seismic systems. Designated seismic systems in structures assigned to Seismic Design Category D, E or F.

1705A.3.3 Seismic Design Category C. The following additional systems and components in structures assigned to Seismic Design Category C:

  1. Heating, ventilating and air-conditioning (HVAC) ductwork containing hazardous materials and anchorage of such ductwork.
  2. Piping systems and mechanical units containing flammable, combustible or highly toxic materials.
  3. Anchorage of electrical equipment used for emergency or standby power systems.

1705A.3.4 Seismic Design Category D. The following additional systems and components in structures assigned to Seismic Design Category D:

  1. Systems required for Seismic Design Category C.
  2. Exterior wall panels and their anchorage.
  3. Suspended ceiling systems and their anchorage.
  4. Access floors and their anchorage.
  5. Steel storage racks and their anchorage, where the importance factor is equal to 1.5 in accordance with Section 15.5.3 of ASCE 7.

1705A.3.5 Seismic Design Category E or F. The following additional systems and components in structures assigned to Seismic Design Category E or F:

  1. Systems required for Seismic Design Categories C and D.
  2. Electrical equipment.

1705A.3.6 Seismic requirements in the statement of special inspections. When Sections 1705A.3 through 1705A.3.5 specify that seismic requirements be included, the statement of special inspections shall identify the following:

  1. The designated seismic systems and seismic-force-resisting systems that are subject to special inspections in accordance with Sections 1705A.3 through 1705A.3.5.
  2. The additional special inspections and testing to be provided as required by Sections 1707A and 1708A and other applicable sections of this code, including the applicable standards referenced by this code.

1705A.4 Wind resistance. The statement of special inspections shall include wind requirements for structures constructed in the following areas:

  1. In wind Exposure Category B, where the 3-second-gust basic wind speed is 120 miles per hour (mph) (52.8 m/s) or greater.
  2. In wind Exposure Category C or D, where the 3-second-gust basic wind speed is 110 mph (49 m/s) or greater.

1705A.4.1 Wind requirements in the statement of special inspections. When Section 1705A.4 specifies that wind requirements be included, the statement of special inspections shall identify the main wind-force-resisting systems and wind-resisting components subject to special inspections as specified in Section 1705A.4.2.

1705A.4.2 Detailed requirements. The statement of special inspections shall include at least the following systems and components:

  1. Roof cladding and roof framing connections.
  2. Wall connections to roof and floor diaphragms and framing.
  3. Roof and floor diaphragm systems, including collectors, drag struts and boundary elements.
  4. Vertical wind-force-resisting systems, including braced frames, moment frames and shear walls.
  5. Wind-force-resisting system connections to the foundation.
  6. Fabrication and installation of systems or components required to meet the impact-resistance requirements of Section 1609.1.2.

Exception: Fabrication of manufactured systems or components that have a label indicating compliance with the wind-load and impact-resistance requirements of this code.

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SECTION 1706A
SPECIAL INSPECTIONS FOR WIND REQUIREMENTS

1706A.1 Special inspections for wind requirements. Special inspections itemized in Sections 1706A.2 through 1706A.4, unless exempted by the exceptions to Section 1704A.1, are required for buildings and structures constructed in the following areas:

  1. In wind Exposure Category B, where the 3-second-gust basic wind speed is 120 miles per hour (52.8 m/sec) or greater.
  2. In wind Exposure Categories C or D, where the 3-second-gust basic wind speed is 110 mph (49 m/sec) or greater.

1706A.2 Structural wood. Continuous special inspection is required during field gluing operations of elements of the main windforce-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of components within the main windforce-resisting system, including wood shear walls, wood diaphragms, drag struts, braces and hold-downs.

Exception: Special inspection is not required for wood shear walls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other components of the main windforce-resisting system, where the fastener spacing of the sheathing is more than 4 inches (102 mm) on center.

1706A.3 Cold-formed steel light-frame construction. Periodic special inspection is required during welding operations of elements of the main windforce-resisting system. Periodic special inspection is required for screw attachment, bolting, anchoring and other fastening of components within the main windforce-resisting system, including shear walls, braces, diaphragms, collectors (drag struts) and hold-downs.

Exception:Special inspection is not required for cold-formed steel light-frame shear walls, braces, diaphragms, collectors (drag struts) and hold-downs where either of the following apply:

  1. The sheathing is gypsum board or fiberboard.
  2. The sheathing is wood structural panel or steel sheets on only one side of the shear wall, shear panel or diaphragm assembly and the fastener spacing of the sheathing is more than 4 inches (102 mm) on center (o.c.).

1706A.4 Wind-resisting components. Periodic special inspection is required for the following systems and components:

  1. Roof cladding.
  2. Wall cladding.

SECTION 1707A
SPECIAL INSPECTIONS FOR SEISMIC RESISTANCE

1707A.1 Special inspections for seismic resistance. Special inspections itemized in Sections 1707A.2 through 1707A.9, unless exempted by the exceptions of Section 1704A.1, 1705A.3, or 1705A.3.1. are required for the following:

  1. The seismic-force-resisting systems in structures assigned to Seismic Design Category C, D, E or F, as determined in Section 1613.
  2. Designated seismic systems in structures assigned to Seismic Design Category D, E or F.
  3. Architectural, mechanical and electrical components in structures assigned to Seismic Design Category C, D, E or F that are required in Sections 1707A.6 and 1707A.7.

1707A.2 Structural steel. Special inspection for structural steel shall be in accordance with the quality assurance plan requirements of AISC 341.

Exceptions:

  1. Special inspections of structural steel in structures assigned to Seismic Design Category C that are not specifically detailed for seismic resistance, with a response modification coefficient, R, of 3 or less, excluding cantilever column systems.
  2. For ordinary moment frames, ultrasonic and magnetic particle testing of complete joint penetration groove welds are only required for demand critical welds.

1707A.3 Structural wood. Continuous special inspection is required during field gluing operations of elements of the seismic-force-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of components within the seismic-force-resisting system, including wood shear walls, wood diaphragms, drag struts, braces, shear panels and hold-downs.

Exception: Special inspection is not required for wood shearwalls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other components of the seismic-force-resisting system, where the fastener spacing of the sheathing is more than 4 inches (102 mm) on center (o.c.)

1707A.4 Cold-formed steel light-frame construction. Periodic special inspection is required during welding operations of elements of the seismic-force-resisting system. Periodic special inspection is required for screw attachment, bolting, anchoring and other fastening of components within the seismic-force-resisting system, including shear walls, braces, diaphragms, collectors (drag struts) and hold-downs.

1707A.5 Storage racks and access floors. Periodic special inspection is required during the anchorage of access floors and storage racks 8 feet (2438 mm) or greater in height in structures assigned to Seismic Design Category D, E or F.

1707A.6 Architectural components. Periodic special inspection during the erection and fastening of exterior cladding, interior and exterior nonbearing walls and interior and exterior

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veneer in structures assigned to Seismic Design Category D, E or F.

Exception:[DSA-SS & DSA-SS/CC] Special inspection is not required for interior nonbearing walls weighing 15 psf (73.5 N/m2) or less.

1707A.7 Mechanical and electrical components. Special inspection for mechanical and electrical equipment shall be as follows:

  1. Periodic special inspection is required during the anchorage of electrical equipment for emergency or standby power systems in structures assigned to Seismic Design Category C, D, E or F;
  2. Periodic special inspection is required during the installation of anchorage of other electrical equipment in structures assigned to Seismic Design Category E or F;
  3. Periodic special inspection is required during installation of piping systems intended to carry flammable, combustible or highly toxic contents and their associated mechanical units in structures assigned to Seismic Design Category C, D, E or F;
  4. Periodic special inspection is required during the installation of HVAC ductwork that will contain hazardous materials in structures assigned to Seismic Design Category C, D, E or F; and
  5. Periodic special inspection is required during the installation of vibration isolation systems in structures assigned to Seismic Design Category C, D, E or F where the construction documents require a nominal clearance of ¼ inch (6.4 mm) or less between the equipment support frame and restraint.

1707A.8 Designated seismic system verifications. The special inspector shall examine designated seismic systems requiring seismic qualification in accordance with Section 1708A.4 and verify that the label, anchorage or mounting conforms to the certificate of compliance.

1707A.9 Seismic isolation and damping systems. Periodic special inspection is required during the fabrication and installation of isolator units and damping devices. Continuous special inspection is required for prototype and production testing of isolator units and damping devices.

SECTION 1708A
STRUCTURAL TESTING FOR SEISMIC RESISTANCE

1708A.1 Testing and qualification for seismic resistance. The testing and qualification specified in Sections 1708A.2 through 1708A.5, unless exempted from special inspections by the exceptions of Section 1704A.1, 1705A.3 or 1705A.3.1 are required as follows:

  1. The seismic-force-resisting systems in structures assigned to Seismic Design Category D, E or F, as determined in Section 1613A shall meet the requirements of Sections 1708A.2 and 1708A.3, as applicable.
  2. Designated seismic systems in structures assigned to Seismic Design Category D, E or F subject to the special certification requirements of ASCE 7 Section 13.2.2 are required to be tested in accordance with Section 1708A.4.
  3. Architectural, mechanical and electrical components in structures assigned to Seismic Design Category D, E or F are required to be tested in accordance with Section 1708A.4 where the general design requirements of ASCE 7 Section 13.2.1, Item 2 for manufacturer's certification are satisfied by testing.
  4. The seismic isolation system in seismically isolated structures and damping devices shall meet the testing requirements of Section 1708A.5.

1708A.2 Concrete reinforcement. Where reinforcement complying with ASTM A 615 is used to resist earth-quake-induced flexural and axial forces in special moment frames, special structural walls and coupling beams connecting special structural walls, in structures assigned to Seismic Design Category B, C, D, E or F as determined in Section 1613, the reinforcement shall comply with Section 21.1.5.2 of ACI 318. Certified mill test reports shall be provided for each shipment of such reinforcement. Where reinforcement complying with ASTM A 615 is to be welded, chemical tests shall be performed to determine weldability in accordance with Section 3.5.2 of ACI 318.

1708A.3 Structural steel. Testing for structural steel shall be in accordance with the quality assurance plan requirements of AISC 341.

Exception: For ordinary moment frames, ultrasonic and magnetic particle testing of complete joint penetration groove welds are only required for demand critical welds.

1708A.4 Seismic certification of nonstructural components. The registered design professional shall state the applicable seismic certification requirements for nonstructural components and designated seismic systems on the construction documents.

  1. The manufacturer of each designated seismic system components subject to the provisions of ASCE 7 Section 13.2.2 shall test or analyze the component and its mounting system or anchorage and submit a certificate of compliance for review and acceptance by the registered design professional responsible for the design of the designated seismic system and for approval by the building official. Certification shall be based on an actual test on a shake table, by three-dimensional shock tests, by an analytical method using dynamic characteristics and forces, by the use of experience data (i.e., historical data demonstrating acceptable seismic performance) or by more rigorous analysis providing for equivalent safety.

[OSHPD 1 & 4] Active or energized components shall be certified exclusively on the basis of approved shake table testing in accordance with ASCE 7 Section 13.2.5 or experience data in accordance with ASCE 7 Section 13.2.6 unless it can be shown that the component is inherently rugged by comparison with similar seismically certified components.

Unless specified otherwise in the test standard, a minimum of two tests are required. Where a range of products

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are tested, the two tests can be on different size products as required by design changes in the internal structures.

Exception: When a single product (and not a product line with more than one product with variations) is certified and manufacturing process is ISO 9001 certified, one dynamic test shall be permitted.

For a multicomponent system, where active or energized components are certified by tests or experience data, connecting elements, attachments and supports can be justified by supporting analysis.

Special seismic certification in accordance with ASCE 7 Section 13.2.2 shall be required for the following systems, equipment, and components, unless specified otherwise by the enforcement agency:

  1. Emergency and standby power systems including generators, turbines, fuel tanks and automatic transfer switches
  2. Elevator equipment (excluding elevator cabs)
  3. Components with hazardous contents (excluding pipes, ducts, and underground tanks)
  4. Smoke control fans
  5. Exhaust fans
  6. Switchgear
  7. Motor control centers
  8. X-Ray machines in fluoroscopy rooms
  9. CT (computerized tomography) Scanners
  10. Air conditioning units
  11. Air handling units
  12. Chillers
  13. Cooling towers (excluding cooling towers designed as nonbuilding structures)
  14. Transformers
  15. Electrical substations
  16. UPS (Inverters) and associated batteries
  17. Distribution panels including electrical panel boards
  18. Control panels including fire alarm, fire suppression, preaction, and auxiliary or remote power supplies

Exceptions:

  1. Equipment and components installed in nonconforming buildings, unless the equipment or component provides a service/system or utility to conforming buildings, or building is designated as SPC 3 or higher.
  2. Equipment and components weighting not more than 20 lbs supported directly on structures (and not mounted on other equipment or components) with supports and attachments in accordance with ASCE 7 Chapter 13 as modified by Section 1615A.
  3. Manufacturer's certification of compliance for the general design requirements of ASCE 7 Section 13.2.1 shall be based on analysis, testing or experience data.

1708A.5 Seismically isolated structures and structures with damping devices. For required system tests, see Sections 17.8 and 18.9 of ASCE 7.

Prototype and production testing and associated acceptance criteria for isolator units and damping devices shall be subject to preapproval by the building official. Testing exemption for similar units shall require approval by the building official.

SECTION 1709A
CONTRACTOR RESPONSIBILITY

1709A.1 Contractor responsibility. Each contractor responsible for the construction of a main wind- or seismic-force-resisting system, designated seismic system or a wind-or seismic-resisting component listed in the statement of special inspections shall submit a written statement of responsibility to the building official and the owner prior to the commencement of work on the system or component. The contractor's statement of responsibility shall contain acknowledgement of awareness of the special requirements contained in the statement of special inspection.

SECTION 1710A
STRUCTURAL OBSERVATIONS

1710A.1 General. Where required by the provisions of Section 1710A.2 or 1710A.3 the owner shall employ a registered design professional to perform structural observations as defined in Section 1702A.

Prior to the commencement of observations, the structural observer shall submit to the building official a written statement identifying the frequency and extent of structural observations.

At the conclusion of the work included in the permit, the structural observer shall submit to the building official a written statement that the site visits have been made and identify any reported deficiencies which, to the best of the structural observer's knowledge, have not been resolved.

1710A.2 Structural observations for seismic resistance. Observation of the construction shall be provided by the architect or engineer in responsible charge as set forth in Title 24, Part 1.

1710A.3 Structural observations for wind requirements. Observation of the construction shall be provided by the architect or engineer in responsible charge as set forth in Title 24, Part 1.

SECTION 1711A
DESIGN STRENGTHS OF MATERIALS

1711A.1 Conformance to standards. The design strengths and permissible stresses of any structural material that are identified by a manufacturer's designation as to manufacture and grade by mill tests, or the strength and stress grade is otherwise confirmed to the satisfaction of the building official, shall conform to the specifications and methods of design of accepted

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engineering practice or the approved rules in the absence of applicable standards.

1711A.2 New materials. For materials that are not specifically provided for in this code, the design strengths and permissible stresses shall be established by tests as provided for in Section 1712A.

SECTION 1712A
ALTERNATIVE TEST PROCEDURE

1712A.1 General. In the absence of approved rules or other approved standards, the building official shall make, or cause to be made, the necessary tests and investigations; or the building official shall accept duly authenticated reports from approved agencies in respect to the quality and manner of use of new materials or assemblies as provided for in Section 104.11. The cost of all tests and other investigations required under the provisions of this code shall be borne by the applicant.

SECTION 1713A
TEST SAFE LOAD

1713A.1 Where required. Where proposed construction is not capable of being designed by approved engineering analysis, or where proposed construction design method does not comply with the applicable material design standard, the system of construction or the structural unit and the connections shall be subjected to the tests prescribed in Section 1715A. The building official accept certified reports of such tests conducted by an approved testing agency, provided that such tests meet the requirements of this code and approved procedures.

SECTION 1714A
IN-SITU LOAD TESTS

1714A.1 General. Whenever there is a reasonable doubt as to the stability or load-bearing capacity of a completed building, structure or portion thereof for the expected loads, an engineering assessment shall be required. The engineering assessment shall involve either a structural analysis or an in-situ load test, or both. The structural analysis shall be based on actual material properties and other as-built conditions that affect stability or load-bearing capacity, and shall be conducted in accordance with the applicable design standard. If the structural assessment determines that the load-bearing capacity is less than that required by the code, load tests shall be conducted in accordance with Section 1714A.2. If the building, structure or portion thereof is found to have inadequate stability or load-bearing capacity for the expected loads, modifications to ensure structural adequacy or the removal of the inadequate construction shall be required.

1714A.2 Test standards. Structural components and assemblies shall be tested in accordance with the appropriate material standards listed in Chapter 35. In the absence of a standard that contains an applicable load test procedure, the test procedure shall be developed by a registered design professional and approved. The test procedure shall simulate loads and conditions of application that the completed structure or portion thereof will be subjected to in normal use.

1714A.3 In-situ load tests. In-situ load tests shall be conducted in accordance with Section 1714A.3.1 or 1714A.3.2 and shall be supervised by a registered design professional. The test shall simulate the applicable loading conditions specified in Chapter 16 as necessary to address the concerns regarding structural stability of the building, structure or portion thereof.

1714A.3.1 Load test procedure specified. Where a standard listed in Chapter 35 contains an applicable load test procedure and acceptance criteria, the test procedure and acceptance criteria in the standard shall apply. In the absence of specific load factors or acceptance criteria, the load factors and acceptance criteria in Section 1714A.3.2 shall apply.

1714A.3.2 Load test procedure not specified. In the absence of applicable load test procedures contained within a standard referenced by this code or acceptance criteria for a specific material or method of construction, such existing structure shall be subjected to a test procedure developed by a registered design professional that simulates applicable loading and deformation conditions. For components that are not a part of the seismic-load-resisting system, the test load shall be equal to two times the unfactored design loads. The test load shall be left in place for a period of 24 hours. The structure shall be considered to have successfully met the test requirements where the following criteria are satisfied:

  1. Under the design load, the deflection shall not exceed the limitations specified in Section 1604.3.
  2. Within 24 hours after removal of the test load, the structure shall have recovered not less than 75 percent of the maximum deflection.
  3. During and immediately after the test, the structure shall not show evidence of failure.

SECTION 1715A
PRECONSTRUCTION LOAD TESTS

1715A.1 General. In evaluating the physical properties of materials and methods of construction that are not capable of being designed by approved engineering analysis or do not comply with applicable material design standards listed in Chapter 35, the structural adequacy shall be predetermined based on the load test criteria established in this section.

1715A.2 Load test procedures specified. Where specific load test procedures, load factors and acceptance criteria are included in the applicable design standards listed in Chapter 35, such test procedures, load factors and acceptance criteria shall apply. In the absence of specific test procedures, load factors or acceptance criteria, the corresponding provisions in Section 1715A.3 shall apply.

1715A.3 Load test procedures not specified. Where load test procedures are not specified in the applicable design standards listed in Chapter 35, the load-bearing and deformation capacity of structural components and assemblies shall be determined on the basis of a test procedure developed by a registered design professional that simulates applicable loading and deformation conditions. For components and assemblies that

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are not a part of the seismic-force-resisting system, the test shall be as specified in Section 1715A.3.1. Load tests shall simulate the applicable loading conditions specified in Chapter 16.

1715A.3.1 Test procedure. The test assembly shall be subjected to an increasing superimposed load equal to not less than two times the superimposed design load. The test load shall be left in place for a period of 24 hours. The tested assembly shall be considered to have successfully met the test requirements if the assembly recovers not less than 75 percent of the maximum deflection within 24 hours after the removal of the test load. The test assembly shall then be reloaded and subjected to an increasing superimposed load until either structural failure occurs or the superimposed load is equal to two and one-half times the load at which the deflection limitations specified in Section 1715A.3.2 were reached, or the load is equal to two and one-half times the superimposed design load. In the case of structural components and assemblies for which deflection limitations are not specified in Section 1715A.3.2, the test specimen shall be subjected to an increasing superimposed load until structural failure occurs or the load is equal to two and one-half times the desired superimposed design load. The allowable superimposed design load shall be taken as the lesser of:

  1. The load at the deflection limitation given in Section 1715A.3.2.
  2. The failure load divided by 2.5.
  3. The maximum load applied divided by 2.5.

1715A.3.2 Deflection. The deflection of structural members under the design load shall not exceed the limitations in Section 1604.3.

1715A.4 Wall and partition assemblies. Load-bearing wall and partition assemblies shall sustain the test load both with and without window framing. The test load shall include all design load components. Wall and partition assemblies shall be tested both with and without door and window framing.

1715A.5 Exterior window and door assemblies. The design pressure rating of exterior windows and doors in buildings shall be determined in accordance with Section 1715A.5.1 or 1715A.5.2.

Exception: Structural wind load design pressures for window units smaller than the size tested in accordance with Section 1715A.5.1 or 1715A.5.2 shall be permitted to be higher than the design value of the tested unit provided such higher pressures are determined by accepted engineering analysis. All components of the small unit shall be the same as the tested unit. Where such calculated design pressures are used, they shall be validated by an additional test of the window unit having the highest allowable design pressure.

1715A.5.1 Exterior windows and doors. Exterior windows and sliding doors shall be tested and labeled as conforming to AAMA/WDMA/CSA101/I.S.2/A440. The label shall state the name of the manufacturer, the approved labeling agency and the product designation as specified in AAMA/WDMA/CSA101/I.S.2/A440. Exterior side-hinged doors shall be tested and labeled as conforming to AAMA/WDMA/CSA101/I.S.2/A440. or comply with Section 1715A.5.2. Products tested and labeled as conforming to AAMA/WDMA/CSA101/I.S.2/A440 shall not be subject to the requirements of Sections 2403.2 and 2403.3.

1715A.5.2 Exterior windows and door assemblies not provided for in Section 1715A.5.1. Exterior window and door assemblies shall be tested in accordance with ASTM E 330. Structural performance of garage doors shall be determined in accordance with either ASTM E 330 or ANSI/DASMA 108, and shall meet the acceptance criteria of ANSI/DASMA 108. Exterior window and door assemblies containing glass shall comply with Section 2403. The design pressure for testing shall be calculated in accordance with Chapter 16. Each assembly shall be tested for 10 seconds at a load equal to 1.5 times the design pressure.

1715A.6 Test specimens. Test specimens and construction shall be representative of the materials, workmanship and details normally used in practice. The properties of the materials used to construct the test assembly shall be determined on the basis of tests on samples taken from the load assembly or on representative samples of the materials used to construct the load test assembly. Required tests shall be conducted or witnessed by an approved agency.

SECTION 1716A
MATERIAL AND TEST STANDARDS

1716A.1 Test standards for joist hangers and connectors.

1716A.1.1 Test standards for joist hangers. The vertical load-bearing capacity, torsional moment capacity and deflection characteristics of joist hangers shall be determined in accordance with ASTM D 1761 using lumber having a specific gravity of 0.49 or greater, but not greater than 0.55, as determined in accordance with AF&PA NDS for the joist and headers.

Exception: The joist length shall not be required to exceed 24 inches (610 mm).

1716A.1.2 Vertical load capacity for joist hangers. The vertical load capacity for the joist hanger shall be determined by testing a minimum of three joist hanger assemblies as specified in ASTM D 1761. If the ultimate vertical load for any one of the tests varies more than 20 percent from the average ultimate vertical load, at least three additional tests shall be conducted. The allowable vertical load of the joist hanger shall be the lowest value determined from the following:

  1. The lowest ultimate vertical load for a single hanger from any test divided by three (where three tests are conducted and each ultimate vertical load does not vary more than 20 percent from the average ultimate vertical load).
  2. The average ultimate vertical load for a single hanger from all tests divided by three (where six or more tests are conducted).
  3. The average from all tests of the vertical loads that produce a vertical movement of the joist with respect to the header of 1⁄8 inch (3.2 mm).171
  4. The sum of the allowable design loads for nails or other fasteners utilized to secure the joist hanger to the wood members and allowable bearing loads that contribute to the capacity of the hanger.
  5. The allowable design load for the wood members forming the connection.

1716A.1.3 Torsional moment capacity for joist hangers. The torsional moment capacity for the joist hanger shall be determined by testing at least three joist hanger assemblies as specified in ASTM D 1761. The allowable torsional moment of the joist hanger shall be the average torsional moment at which the lateral movement of the top or bottom of the joist with respect to the original position of the joist is 1⁄8 inch (3.2 mm).

1716A.1.4 Design value modifications for joist hangers. Allowable design values for joist hangers that are determined by Item 4 or 5 in Section 1716A.1.2 shall be permitted to be modified by the appropriate duration of loading factors as specified in AF&PA NDS but shall not exceed the direct loads as determined by Item 1, 2 or 3 in Section 1716A.1.2. Allowable design values determined by Item 1, 2 or 3 in Section 1716A.1.2 shall not be modified by duration of loading factors.

1716A.2 Concrete and clay roof tiles.

1716A.2.1 Overturning resistance. Concrete and clay roof tiles shall be tested to determine their resistance to overturning due to wind in accordance with SBCCI SSTD 11 and Chapter 15.

1716A.2.2 Wind tunnel testing. When roof tiles do not satisfy the limitations in Chapter 16 for rigid tile, a wind tunnel test shall be used to determine the wind characteristics of the concrete or clay tile roof covering in accordance with SBCCI SSTD 11 and Chapter 15.

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CALIFORNIA BUILDING CODE-MATRIX ADOPTION TABLE
CHAPTER 18 - SOILS AND FOUNDATIONS
Adopting agencyBSCSFMHCDDSAOSHPDCSADPHAGRDWRCECCASLSLC
121-ACACSSSS/CC1234
Adopt entire chapterX         X         
Adopt entire chapter as
amended (amended sections
listed below)		  XX     X          
Adopt only those sections that
are listed below		                    
Chapter/Section                    
1801.2  XX                
1803.1.1 - 1803.1.1.3  XX                
1803.2          X         
1803.6          X         
1803.7          X         
1810.3.1.5.1          X         
1810.3.10.4.1          X         
173 174

CHAPTER 18
SOILS AND FOUNDATIONS

This chapter has been revised in its entirety; there will be no marginal markings.

SECTION 1801
GENERAL

1801.1 Scope. The provisions of this chapter shall apply to building and foundation systems.

1801.2 Design basis. Allowable bearing pressures, allowable stresses and design formulas provided in this chapter shall be used with the allowable stress design load combinations specified in Section 1605.3. The quality and design of materials used structurally in excavations and foundations shall comply with the requirements specified in Chapters 16, 19, 21, 22 and 23 of this code. Excavations and fills shall also comply with Chapter 33.

[HCD 1] For limited-density owner-built rural dwellings, pier foundations, stone masonry footings and foundations, pressure-treated lumber, poles or equivalent foundation materials or designs may be used, provided that the bearing is sufficient for the purpose intended.

SECTION 1802
DEFINITIONS

1802.1 Definitions. The following words and terms shall, for the purposes of this chapter, have the meanings shown herein.

DEEP FOUNDATION. A deep foundation is a foundation element that does not satisfy the definition of a shallow foundation.

DRILLED SHAFT. A drilled shaft is a cast-in-place deep foundation element constructed by drilling a hole (with or without permanent casing) into soil or rock and filling it with fluid concrete.

Socketed drilled shaft. A socketed drilled shaft is a drilled shaft with a permanent pipe or tube casing that extends down to bedrock and an uncased socket drilled into the bedrock.

HELICAL PILE. Manufactured steel deep foundation element consisting of a central shaft and one or more helical bearing plates. A helical pile is installed by rotating it into the ground. Each helical bearing plate is formed into a screw thread with a uniform defined pitch.

MICROPILE. A micropile is a bored, grouted-in-place deep foundation element that develops its load-carrying capacity by means of a bond zone in soil, bedrock or a combination of soil and bedrock.

SHALLOW FOUNDATION. A shallow foundation is an individual or strip footing, a mat foundation, a slab-on-grade foundation or a similar foundation element.

SECTION 1803
GEOTECHNICAL INVESTIGATIONS

1803.1 General. Geotechnical investigations shall be conducted in accordance with Section 1803.2 and reported in accordance with Section 1803.6. Where required by the building official or where geotechnical investigations involve in-situtesting, laboratory testing or engineering calculations, such investigations shall be conducted by a registered design professional.

1803.1.1 General and where required for applications listed in Section 1.8.2.1.1 regulated by the Department of Housing and Community Development. [HCD 1] Foundation and soils investigations shall be conducted in conference with Health and Safety Code Sections 17953 through 17955 as summarized below.

1803.1.1.1 Preliminary soil report. Each city, county, or city and county shall enact an ordinance which requires a preliminary soil report, prepared by a civil engineer who is registered by the state. The report shall be based upon adequate test borings or excavations, of every subdivision, where a tentative and final map is required pursuant to Section 66426 of the Government Code.

The preliminary soil report may be waived if the building department of the city, county or city, and county, or other enforcement agency charged with the administration and enforcement of the provisions of this part, shall determine that, due to the knowledge such department has as to the soil qualities of the soil of the subdivision or lot, no preliminary analysis is necessary.

1803.1.1.2 Soil investigation by lot, necessity, preparation, and recommendations. If the preliminary soil report indicates the presence of critically expansive soils or other soil problems which, if not corrected, would lead to structural defects, such ordinance shall require a soil investigation of each lot in the subdivision.

The soil investigation shall be prepared by a civil engineer who is registered in this state. It shall recommend corrective action which is likely to prevent structural damage to each dwelling proposed to be constructed on the expansive soil.

1803.1.1.3 Approval, building permit conditions, appeal. The building department of each city, county or city and county, or other enforcement agency charged with the administration and enforcement of the provisions of this part, shall approve the soil investigation if it determines that the recommended action is likely to prevent structural damage to each dwelling to be constructed. As a condition to the building permit, the ordinance shall require that the approved recommended

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action be incorporated in the construction of each dwelling. Appeal from such determination shall be to the local appeals board.

1803.2 Investigations required. Geotechnical investigations shall be conducted in accordance with Sections 1803.3 through 1803.5.

Exception: The building official shall be permitted to waive the requirement for a geotechnical investigation where satisfactory data from adjacent areas is available that demonstrates an investigation is not necessary for any of the conditions in Sections 1803.5.1 through 1803.5.6 and Sections 1803.5.10 and 1803.5.11.

[OSHPD 2] Geotechnical reports are not required for one-story, wood-frame and light-steel-frame buildings of Type V construction and 4,000 square feet (371 m2) or less in floor area, not located within Earthquake Fault Zones or Seismic Hazard Zones as shown in the most recently published maps from the California Geological Survey (CGS). Allowable foundation and lateral soil pressure values may be determined from Table 1804.2.

1803.3 Basis of investigation. Soil classification shall be based on observation and any necessary tests of the materials disclosed by borings, test pits or other subsurface exploration made in appropriate locations. Additional studies shall be made as necessary to evaluate slope stability, soil strength, position and adequacy of load-bearing soils, the effect of moisture variation on soil-bearing capacity, compressibility, liquefaction and expansiveness.

1803.3.1 Scope of investigation. The scope of the geotechnical investigation including the number and types of borings or soundings, the equipment used to drill or sample, the in-situ testing equipment and the laboratory testing program shall be determined by a registered design profesional.

1803.4 Qualified representative. The investigation procedure and apparatus shall be in accordance with generally accepted engineering practice. The registered design professional shall have a fully qualified representative on site during all boring or sampling operations.

1803.5 Investigated conditions. Geotechnical investigations shall be conducted as indicated in Sections 1803.5.1 through 1803.5.12.

1803.5.1 Classification. Soil materials shall be classified in accordance with ASTM D 2487.

1803.5.2 Questionable soil. Where the classification, strength or compressibility of the soil is in doubt or where a load-bearing value superior to that specified in this code is claimed, the building official shall be permitted to require that a geotechnical investigation be conducted.

1803.5.3 Expansive soil. In areas likely to have expansive soil, the building official shall require soil tests to determine where such soils do exist.

Soils meeting all four of the following provisions shall be considered expansive, except that tests to show compliance with Items 1,2 and 3 shall not be required if the test prescribed in Item 4 is conducted:

  1. Plasticity index (PI) of 15 or greater, determined in accordance with ASTM D 4318.
  2. More than 10 percent of the soil particles pass a No. 200 sieve (75 µm), determined in accordance with ASTM D 422.
  3. More than 10 percent of the soil particles are less than 5 micrometers in size, determined in accordance with ASTM D 422.
  4. Expansion index greater than 20, determined in accordance with ASTM D 4829.

1803.5.4 Ground-water table. A subsurface soil investigation shall be performed to determine whether the existing ground-water table is above or within 5 feet (1524 mm) below the elevation of the lowest floor level where such floor is located below the finished ground level adjacent to the foundation.

Exception: A subsurface soil investigation to determine the location of the ground-water table shall not be required where waterproofing is provided in accordance with Section 1805.

1803.5.5 Deep foundations. Where deep foundations will be used, a geotechnical investigation shall be conducted and shall include all of the following, unless sufficient data upon which to base the design and installation is otherwise available:

  1. Recommended deep foundation types and installed capacities.
  2. Recommended center-to-center spacing of deep foundation elements.
  3. Driving criteria.
  4. Installation procedures.
  5. Field inspection and reporting procedures (to include procedures for verification of the installed bearing capacity where required).
  6. Load test requirements.
  7. Suitability of deep foundation materials for the intended environment.
  8. Designation of bearing stratum or strata.
  9. Reductions for group action, where necessary.

1803.5.6 Rock strata. Where subsurface explorations at the project site indicate variations or doubtful characteristics in the structure of the rock upon which foundations are to be constructed, a sufficient number of borings shall be made to a depth of not less than 10 feet (3048 mm) below the level of the foundations to provide assurance of the soundness of the foundation bed and its load-bearing capacity.

1803.5.7 Excavation near foundations. Where excavation will remove lateral support from any foundation, an investi-

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gation shall be conducted to assess the potential consequences and address mitigation measures.

1803.5.8 Compacted fill material. Where shallow foundations will bear on compacted fill material more than 12 inches (305 mm) in depth, a geotechnical investigation shall be conducted and shall include all of the following:

  1. Specifications for the preparation of the site prior to placement of compacted fill material.
  2. Specifications for material to be used as compacted fill.
  3. Test methods to be used to determine the maximum dry density and optimum moisture content of the material to be used as compacted fill.
  4. Maximum allowable thickness of each lift of compacted fill material.
  5. Field test method for determining the in-place dry density of the compacted fill.
  6. Minimum acceptable in-place dry density expressed as a percentage of the maximum dry density determined in accordance with Item 3.
  7. Number and frequency of field tests required to determine compliance with Item 6.

1803.5.9 Controlled low-strength material (CLSM). Where shallow foundations will bear on controlled lowstrength material (CLSM), a geotechnical investigation shall be conducted and shall include all of the following:

  1. Specifications for the preparation of the site prior to placement of the CLSM.
  2. Specifications for the CLSM.
  3. Laboratory or field test method(s) to be used to determine the compressive strength or bearing capacity of the CLSM.
  4. Test methods for determining the acceptance of the CLSM in the field.
  5. Number and frequency of field tests required to determine compliance with Item 4.

1803.5.10 Alternate setback and clearance. Where setbacks or clearances other than those required in Section 1808.7 are desired, the building official shall be permitted to require a geotechnical investigation by a registered design professional to demonstrate that the intent of Section 1808.7 would be satisfied. Such an investigation shall include consideration of material, height of slope, slope gradient, load intensity and erosion characteristics of slope material.

1803.5.11 Seismic Design Categories C through F. For structures assigned to Seismic Design Category C, D, E or F in accordance with Section 1613, a geotechnical investigation shall be conducted, and shall include an evaluation of all of the following potential geologic and seismic hazards:

  1. Slope instability.
  2. Liquefaction.
  3. Differential settlement.
  4. Surface displacement due to faulting or lateral spreading.

1803.5.12 Seismic Design Categories D through F. For structures assigned to Seismic Design Category D, E or Fin accordance with Section 1613, the geotechnical investigation required by Section 1803.5.11, shall also include:

  1. The determination of lateral pressures on foundation walls and rataining walls due to earthquake motions.
  2. The potential for liquefaction and soil strength loss evaluated for site peak ground accelerations, magnitudes and source characteristics consistent with the design earthquake ground motions. Peak ground acceleration shall be permitted to be determined based on a site-specific study taking into account soil amplification effects, as specified in Chapter 21 of ASCE 7, or, in the absence of such a study, peak ground accelerations shall be assumed equal to SDs/2.5, where SDS is determined in accordance with Section 1613.5.4.
  3. An assessment of potential consequences of liquefaction and soil strength loss, including estimation of differential settlement, lateral movement, lateral loads on foundations, reduction in foundation soil-bearing capacity, increases in lateral pressures on retaining walls and flotation of buried structures.
  4. Discussion of mitigation measures such as, but not limited to, ground stabilization, selection of appropriate foundation type and depths, selection of appropriate structural systems to accommodate anticipated displacements and forces, or any combination of these measures and how they shall be considered in the design of the structure.

1803.6 Reporting. Where geotechnical investigations are required, a written report of the investigations shall be submitted to the building official by the owner or authorized agent at the time of permit application. This geotechnical report shall include, but need not be limited to, the following information:

  1. A plot showing the location of the soil investigations.
  2. A complete record of the soil boring and penetration test logs and soil samples.
  3. A record of the soil profile.
  4. Elevation of the water table, if encountered.
  5. Recommendations for foundation type and design criteria, including but not limited to: bearing capacity of natural or compacted soil; provisions to mitigate the effects of expansive soils; mitigation of the effects of liquefaction, differential settlement and varying soil strength; and the effects of adjacent loads.
  6. Expected total and differential settlement.
  7. Deep foundation information in accordance with Section 1803.5.5.
  8. Special design and construction provisions for foundations of structures founded on expansive soils, as necessary.177
  9. Compacted fill material properties and testing in accordance with Section 1803.5.8.
  10. Controlled low-strength material properties and testing in accordance with Section 1803.5.9.
  11. [OSHPD 2] The report shall consider the effects of seismic hazard in accordance with Section 1803.7.

1803.7 Engineering geologic reports. [OSHPD 2]

1803.7.1 Geologic and earthquake engineering reports shall be required for all proposed construction.

Exceptions:

  1. Reports are not required for one-story, woodframe and light-steel-frame buildings of Type V construction and 4,000 square feet (371 m2) or less in floor area, not located within Earthquake Fault Zones or Seismic Hazard Zones as shown in the most recently published maps from the California Geological Survey (CGS); nonstructural, associated structural or voluntary structural alterationsand incidental structural additions or alterations, and structural repairs for other than earthquake damage (See Section 3402A.1 for definitions of terms in this section).
  2. A previous report for a specific site may be resubmitted, provided that a reevaluation is made and the report is found to be currently appropriate.

1803.7.2 The purpose of the engineering geologic report shall be to identify geologic and seismic conditions that may require project mitigations. The reports shall contain data which provide an assessment of the nature of the site and potential for earthquake damage based on appropriate investigations of the regional and site geology, project foundation conditions and the potential seismic shaking at the site. The report shall be prepared by a California-certified engineering geologist in consultation with a California-registered geotechnical engineer.

The preparation of the engineering geologic report shall consider the most recent CGS Note 48; Checklist for the Review of Engineering Geology and Seismology Reports for California Public School, Hospitals, and Essential Services Buildings. In addition, the most recent version of CGS Special Publication 42, Fault Rupture Hazard Zones in California, shall be considered for project sites proposed within an Alquist-Priolo Earthquake Fault Zone, The most recent version of CGS Special Publication 117, Guidelines for Evaluating and Mitigating Seismic Hazards in California, shall be considered for project sites proposed within a Seismic Hazard Zone. All conclusions shall be fully supported by satisfactory data and analysis.

In addition to requirements in Sections 1803.5.11 and 1803.5.12, the report shall include, but shall not be limited to, the following:

  1. Geologic investigation.
  2. Evaluation of the known active and potentially active faults, both regional and local.
  3. Ground-motion parameters, as required by Section 1613 and ASCE 7.

SECTION 1804
EXCAVATION, GRADING AND FILL

1804.1 Excavation near foundations. Excavation for any purpose shall not remove lateral support from any foundation without first underpinning or protecting the foundation against settlement or lateral translation.

1804.2 Placement of backfill. The excavation outside the foundation shall be backfilled with soil that is free of organic material, construction debris, cobbles and boulders or with a controlled low-strength material (CLSM). The backfill shall be placed in lifts and compacted in a manner that does not damage the foundation or the waterproofing or dampproofing material.

Exception: CLSM need not be compacted.

1804.3 Site grading. The ground immediately adjacent to the foundation shall be sloped away from the building at a slope of not less than one unit vertical in 20 units horizontal (5-percent slope) for a minimum distance of 10 feet (3048 mm) measured perpendicular to the face of the wall. If physical obstructions or lot lines prohibit 10 feet (3048 mm) of horizontal distance, a 5-percent slope shall be provided to an approved alternative method of diverting water away from the foundation. Swales used for this purpose shall be sloped a minimum of 2 percent where located within 10 feet (3048 mm) of the building foundation. Impervious surfaces within 10 feet (3048 mm) of the building foundation shall be sloped a minimum of 2 percent away from the building.

Exception: Where climatic or soil conditions warrant, the slope of the ground away from the building foundation shall be permitted to be reduced to not less than one unit vertical in 48 units horizontal (2-percent slope).

The procedure used to establish the final ground level adjacent to the foundation shall account for additional settlement of the backfill.

1804.4 Grading and fill in flood hazard areas. In flood hazard areas established in Section 1612.3, grading and/or fill shall not be approved:

  1. Unless such fill is placed, compacted and sloped to minimize shifting, slumping and erosion during the rise and fall of flood water and, as applicable, wave action.
  2. In floodways, unless it has been demonstrated through hydrologic and hydraulic analyses performed by a registered design professional in accordance with standard engineering practice that the proposed grading or fill, or both, will not result in any increase in flood levels during the occurrence of the design flood.
  3. In flood hazard areas subject to high-velocity wave action, unless such fill is conducted and/or placed to avoid diversion of water and waves toward any building or structure.
  4. Where design flood elevations are specified but floodways have not been designated, unless it has been demonstrated that the cumulative effect of the proposed178 flood hazard area encroachment, when combined with all other existing and anticipated flood hazard area encroachment, will not increase the design flood elevation more than 1 foot (305 mm) at any point.

1804.5 Compacted fill material. Where shallow foundations will bear on compacted fill material, the compacted fill shall comply with the provisions of an approved geotechnical report, as set forth in Section 1803.

Exception: Compacted fill material 12 inches (305 mm) in depth or less need not comply with an approved report, provided the in-place dry density is not less than 90 percent of the maximum dry density at optimum moisture content determined in accordance with ASTM D 1557. The compaction shall be verified by special inspection in accordance with Section 1704.7.

1804.6 Controlled low-strength material (CLSM). Where shallow foundations will bear on controlled low-strength material (CLSM), the CLSM shall comply with the provisions of an approved geotechnical report, as set forth in Section 1803.

SECTION 1805
DAMPPROOFING AND WATERPROOFING

1805.1 General. Walls or portions thereof that retain earth and enclose interior spaces and floors below grade shall be water proofed and dampproofed in accordance with this section, with the exception of those spaces containing groups other than residential and institutional where such omission is not detrimental to the building or occupancy.

Ventilation for crawl spaces shall comply with Section 1203.4.

1805.1.1 Story above grade plane. Where a basement is considered a story above grade plane and the finished ground level adjacent to the basement wall is below the basement floor elevation for 25 percent or more of the perimeter, the floor and walls shall be dampproofed in accordance with Section 1805.2 and a foundation drain shall be installed in accordance with Section 1805.4.2. The foundation drain shall be installed around the portion of the perimeter where the basement floor is below ground level. The provisions of Sections 1803.5.4, 1805.3 and 1805.4.1 shall not apply in this case.

1805.1.2 Under-floor space. The finished ground level of an under-floor space such as a crawl space shall not be located below the bottom of the footings. Where there is evidence that the ground-water table rises to within 6 inches (152 mm) of the ground level at the outside building perimeter, or that the surface water does not readily drain from the building site, the ground level of the under-floor space shall be as high as the outside finished ground level, unless an approved drainage system is provided. The provisions of Sections 1803.5.4, 1805.2, 1805.3 and 1805.4 shall not apply in this case.

1805.1.2.1 Flood hazard areas. For buildings and structures in flood hazard areas as established in Section 1612.3, the finished ground level of an under-floor space such as a crawl space shall be equal to or higher than the outside finished ground level on at least one side.

Exception: Under-floor spaces of Group R-3 buildings that meet the requirements of FEMA/FIA-TB-11.

1805.1.3 Ground-water control. Where the ground-water table is lowered and maintained at an elevation not less than 6 inches (152 mm) below the bottom of the lowest floor, the floor and walls shall be dampproofed in accordance with Section 1805.2. The design of the system to lower the ground-water table shall be based on accepted principles of engineering that shall consider, but not necessarily be limited to, permeability of the soil, rate at which water enters the drainage system, rated capacity of pumps, head against which pumps are to operate and the rated capacity of the disposal area of the system.

1805.2 Dampproofing. Where hydrostatic pressure will not occur as determined by Section 1803.5.4, floors and walls for other than wood foundation systems shall be dampproofed in accordance with this section. Wood foundation systems shall be constructed in accordance with AF&PA PWF.

1805.2.1 Floors. Dampproofing materials for floors shall be installed between the floor and the base course required by Section 1805.4.1, except where a separate floor is provided above a concrete slab.

Where installed beneath the slab, dampproofing shall consist of not less than 6-mil (0.006 inch; 0.152 mm) polyethylene with joints lapped not less than 6 inches (152 mm), or other approved methods or materials. Where permitted to be installed on top of the slab, dampproofing shall consist of mopped-on bitumen, not less than 4-mil (0.004 inch; 0.102 mm) polyethylene, or other approved methods or materials. Joints in the membrane shall be lapped and sealed in accordance with the manufacturer′s installation instructions.

1805.2.2 Walls. Dampproofing materials for walls shall be installed on the exterior surface of the wall, and shall extend from the top of the footing to above ground level.

Dampproofing shall consist of a bituminous material, 3 pounds per square yard (16 N/m2) of acrylic modified cement, 1⁄8 inch (3.2 mm) coat of surface-bonding mortar complying with ASTM C 887, any of the materials permitted for waterproofing by Section 1805.3.2 or other approved methods or materials.

1805.2.2.1 Surface preparation of walls. Prior to application of dampproofing materials on concrete walls, holes and recesses resulting from the removal of from ties shall be sealed with a bituminous material or other approved methods or materials. Unit masonry walls shall be parged on the exterior surface below ground level with not less than 3⁄8; inch (9.5 mm) of portland cement mortar. The parging shall be coved at the footing.

Exception: Parging of unit masonry walls is not required where a material is approved for direct application to the masonry.

1805.3 Waterproofing. Where the ground-water investigation required by Section 1803.5.4 indicates that a hydrostatic pressure condition exists, and the design does not include a

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ground-water control system as described in Section 1805.1.3, walls and floors shall be waterproofed in accordance with this section.

1805.3.1 Floors. Floors required to be waterproofed shall be of concrete and designed and constructed to withstand the hydrostatic pressures to which the floors will be subjected.

Waterproofing shall be accomplished by placing a membrane of rubberized asphalt, butyl rubber, fully adhered/fully bonded HDPE or polyolefin composite membrane or not less than 6-mil [0.006 inch (0.152 mm)] polyvinyl chloride with joints lapped not less than 6 inches (152 mm) or other approved materials under the slab. Joints in the membrane shall be lapped and sealed in accordance with the manufacturer’s installation instructions.

1805.3.2 Walls. Walls required to be waterproofed shall be of concrete or masonry and shall be designed and constructed to withstand the hydrostatic pressures and other lateral loads to which the walls will be subjected.

Waterproofing shall be applied from the bottom of the wall to not less than 12 inches (305 mm) above the maximum elevation of the ground-water table. The remainder of the wall shall be dampproofed in accordance with Section 1805.2.2. Waterproofing shall consist of two-plyhot-mopped felts, not less than 6-mil (0.006 inch; 0.152 mm) polyvinyl chloride, 40-mil (0.040 inch; 1.02 mm) polymer-modified asphalt, 6-mil (0.006 inch; 0.152 mm) polyethylene or other approved methods or materials capable of bridging nonstructural cracks. Joints in the membrane shall be lapped and sealed in accordance with the manufacturer’s installation instructions.

1805.3.2.1 Surface preparation of walls. Prior to the application of waterproofing materials on concrete or masonry walls, the walls shall be prepared in accordance with Section 1805.2.2.1.

1805.3.3 Joints and penetrations. Joints in walls and floors, joints between the wall and floor and penetrations of the wall and floor shall be made water-tight utilizing approved methods and materials.

1805.4 Subsoil drainage system. Where a hydrostatic pressure condition does not exist, dampproofing shall be provided and a base shall be installed under the floor and a drain installed around the foundation perimeter. A subsoil drainage system designed and constructed in accordance with Section 1805.1.3 shall be deemed adequate for lowering the ground-water table.

1805.4.1 Floor base course. Floors of basements, except as provided for in Section 1805.1.1, shall be placed over a floor base course not less than 4 inches (102 mm) in thickness that consists of gravel or crushed stone containing not more than 10 percent of material that passes through a No.4(4.75 mm) sieve.

Exception: Where a site is located in well-drained gravel or sand/gravel mixture soils, a floor base course is not required.

1805.4.2 Foundation drain. A drain shall be placed around the perimeter of a foundation that consists of gravel or crushed stone containing not more than 10-percent material that passes through a No.4 (4.75 mm) sieve. The drain shall extend a minimum of 12 inches (305 mm) beyond the outside edge of the footing. The thickness shall be such that the bottom of the drain is not higher than the bottom of the base under the floor, and that the top of the drain is not less than 6 inches (152 mm) above the top of the top of the footing. The top of the drain shall be covered with an approved filter membrane material. Where a drain tile or perforated pipe is used, the invert of the pipe or tile shall not be higher than the floor elevation. The top of joints or the top of perforations shall be protected with an approved filter membrane material. The pipe or tile shall be placed on not less than 2 inches (51 mm) of gravel of crushed stone complying with Section 1805.4.1, and shall be covered with not less than 6 inches (152 mm) of the same material.

1805.4.3 Drainage discharge. The floor base and foundation perimeter drain shall discharge by gravity or mechanical means into an approved drainage system that complies with the California Plumbing Code.

Exception: Where a site is located in well-drained gravel or sand/gravel mixture soils, a dedicated drainage system is not required.

SECTION 1806
PRESUMPTIVE LOAD-BEARING VALUES OF SOILS

1806.1 Load combinations. The presumptive load-bearing values provided in Table 1806.2 shall be used with the allowable stress design load combinations specified in Section 1605.3. The values of vertical foundation pressure and lateral bearing pressure given in Table 1806.2 shall be permitted to be increased by one-third where used with the alternative basic load combinations of section 1605.3.2 that include wind or earthquake loads.

1806.2 Presumptive load-bearing values. The load-bearing values used in design for supporting soils near the surface shall not exceed the values specified in Table 1806.2 unless data to substantiate the use of higher values are submitted and approved. Where the building official has reason to doubt the classification, strength or compressibility of the soil, the requirements of Section 1803.5.2 shall be satisfied.

Presumptive load-bearing values shall apply to materials with similar physical characteristics and dispositions. Mud, organic silt, organic clays, peat or unprepared fill shall not be assumed to have a presumptive load-bearing capacity unless data to substantiate the use of such a value are submitted.

Exception: A presumptive load-bearing capacity shall be permitted to be used where the building official deems the load-bearing capacity or mud, organic silt or unprepared fill is adequate for the support of lightweight or temporary structures.

1806.3 Lateral load resistance. Where the presumptive values of Table 1806.2 are used to determine resistance to lateral loads, the calculations shall be in accordance with Sections 1806.3.1 through 1806.3.4.

180

1806.3.1 Combined resistance. The total resistance to lateral loads shall be permitted to be determined by combining the values derived from the lateral bearing pressure and the lateral sliding resistance specified in Table 1806.2.

1806.3.2 Lateral sliding resistance limit. For clay, sandy clay, silty clay, clayey silt, silt and sandy silt, in no case shall the lateral sliding resistance exceed one-half the dead load.

1806.3.3 Increase for depth. The lateral bearing pressures specified in Table 1806.2 shall be permitted to be increased by the tabular value for each additional foot (305 mm) of depth to a maximum of 15 times the tabular value.

1806.3.4 Increase for poles. Isolated poles for uses such as flagpoles or signs and poles used to support buildings that are not adversely affected by a ½ inch (12.7 mm) motion at the ground surface due to short-term lateral loads shall be permitted to be designed using lateral bearing pressures equal to two times the tabular values.

SECTION 1807
FOUNDATION WALLS, RETAINING WALLS AND EMBEDDED POSTS AND POLES

1807.1 Foundation walls. Foundation walls shall be designed and constructed in accordance with Sections 1807.1.1 through 1807.1.6. Foundation walls shall be supported by foundations designed in accordance with Section 1808.

1807.1.1 Design lateral soil loads. Foundation walls shall be designed for the lateral soil loads set forth in Section 1610.

1807.1.2 Unbalanced backfill height. Unbalanced backfill height is the difference in height between the exterior finish ground level and the lower of the top of the concrete footing that supports the foundation wall or the interior finish ground level. Where an interior concrete slab on grade is provided and is in contact with the interior surface of the foundation wall, the unbalanced backfill height shall be permitted to be measured from the exterior finish ground level to the top of the interior concrete slab.

1807.1.3 Rubble stone foundation walls. Foundation walls of rough or random rubble stone shall not be less than 16 inches (406 mm) thick. Rubble stone shall not be used for foundation walls of structures assigned to Seismic Design Category C, D, E or F.

1807.1.4 Permanent wood foundation systems. Permanent wood foundation systems shall be designed and installed in accordance with AF&PA PWF. Lumber and plywood shall be treated in accordance with AWPA U1 (Commodity Specification A, Use Category 4B and Section 5.2) and shall be identified in accordance with Section 2303.1.8.1.

1807.1.5 Concrete and masonry foundation walls. Concrete and masonry foundation walls shall be designed in accordance with Chapter 19 or 21, as applicable.

Exception: Concrete and masonry foundation walls shall be permitted to be designed and constructed in accordance with Section 1807.1.6.

1807.1.6. Prescriptive design of concrete and masonry foundation walls. Concrete and masonry foundation walls that are laterally supported at the top and bottom shall be permitted to be designed and constructed in accordance with this section.

1807.1.6.1 Foundation wall thickness. The thickness of prescriptively designed foundation walls shall not be less than the thickness of the wall supported, except that foundation walls of at least 8-inch (203 mm) nominal width shall be permitted to support brick-veneered frame walls and 10-inch-wide (254 mm) cavity walls provided the requirements of Section 1807.1.6.2 or 1807.1.6.3 are met.

TABLE 1806.2
PRESUMPTIVE LOAD-BEARING VALUES
CLASS OF MATERIALSVERTICAL FOUNDATION PRESSURE (psf)LATERAL BEARING PRESSURE (psf/ft below natural grade)LATERAL SLIDING RESISTANCE
Coefficient of frictionaCohesion (psf)b
For SI: 1 pound per square foot=0.0479 kPa, 1 pound per square foot per foot= 0.157 kPa/m.
a. Coefficient to be multiplied by the dead load.
b. Cohesion value to be multiplied by the contact area, as limited by Section 1806.3.2.
1. Crystalline bedrock12,0001,2000.70—
2. Sedimentary and foliated rock4,0004000.35—
3. Sandy gravel and/or gravel (GW and GP)3,0002000.35—
4. Sand, silty sand, clayey sand, silty gravel and clayey gravel (SW, SP, SM, SC, GM and GC)2,0001500.25—
5. Clay, sandy clay, silty clay, clayey silt, silt and sandy silt (CL, ML, MH and CH)1,500100—130
181

1807.1.6.2 Concrete foundation walls. Concrete foundation walls shall comply with the following:

  1. The thickness shall comply with the requirements of Table 1807.1.6.2.
  2. The size and spacing of vertical reinforcement shown in Table 1807.1.6.2 is based on the use of reinforcement with a minimum yield strength of 60,000 pounds per square inch (psi) (414 MPa). Vertical reinforcement with a minimum yield strength of 40,000 psi (276 MPa) or 50,000 psi (345 MPa) shall be permitted, provided the same size bar is used and the spacing shown in the table is reduced by multiplying the spacing by 0.67 or 0.83, respectively.
  3. Vertical reinforcement, when required, shall be placed nearest the inside face of the wall a distance, d, from the outside face (soil face) of the wall. The distance, d, is equal to the wall thickness, t, minus 1.25 inches (32 mm) plus one-half the bar diameter, db,[d=t–(1.25+db/2)]. The reinforcement shall be placed within a tolerance of ± 3⁄8 inch (9.5 mm) where d is less than or equal to 8 inches (203 mm) or ± ½ inch (12.7 mm) where d is greater than 8 inches (203 mm).
  4. In lieu of the reinforcement shown in Table 1807.1.6.2, smaller reinforcing bar sizes with closer spacings that provide an equivalent cross-sectional area of reinforcement per unit length shall be permitted.
TABLE 1807.1.6.2
CONCRETE FOUNDATION WALLSb,c
MAXIMUM WALL HEIGHT (feet)MAXIMUM UNBALANCED BACKFILL HEIGHTe(feet)MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING(inches)
Design lateral soil loada (psf per foot of depth)
30d45d60
Minimum wall thickness(inches)
7.59.511.57.59.511.57.59.511.5
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157kPa⁄m.
a. For design lateral soil loads, see Section 1610.
b. Provisions for this table are based on design and construction requirements specified in Section 1807.1.6.2.
c. “PC” means plain concrete.
d. Where unbalanced backfill height exceeds 8 feet and design lateral soil loads from Table 1610.1 are used, the requirements for 30 and 45 psf per foot of depth are not applicable (see Section 1610).
e. For height of unbalanced backfill, see Section 1807.1.2.
54PCPCPCPCPCPCPCPCPC
5PCPCPCPCPCPCPCPCPC
64PCPCPCPCPCPCPCPCPC
5PCPCPCPCPCPCPCPCPC
6PCPCPCPCPCPCPCPCPC
74PCPCPCPCPCPCPCPCPC
5PCPCPCPCPCPCPCPCPC
6PCPCPCPCPCPC#5 at 48PCPC
7PCPCPC#5 at 46PCPC#5 at 46PCPC
84PCPCPCPCPCPCPCPCPC
5PCPCPCPCPCPCPCPCPC
6PCPCPCPCPCPC#5 at 41PCPC
7PCPCPC#5 at 41PCPC#6 at 43PCPC
8#5 at 47PCPC#6 at 43PCPC#6 at 32#6 at 44PC
94PCPCPCPCPCPCPCPCPC
5PCPCPCPCPCPCPCPCPC
6PCPCPCPCPCPC#5 at 39PCPC
7PCPCPC#5 at 37PC#6 at 38#5 at 37PCPC
8#5 at 41PCPC#6 at 38#5 at 37PC#7 at 39#6 at 39#4 at 48
9d#6 at 46PCPC#7 at 41#6 at 41PC#7 at 31#7 at 41#6 at 39
104PCPCPCPCPCPCPCPCPC
5PCPCPCPCPCPCPCPCPC
6PCPCPCPCPCPC#5 at 37PCPC
7PCPCPC#6 at 48PCPC#6 at 35#6 at 48PC
8#5 at 38PCPC#7 at 47#6 at 47PC#7 at 35#7 at 47#6 at 45
9d#6 at 41#4 at 48PC#7 at 37#7 at 48#4 at 48#6 at 22#7 at 37#7 at 47
10d#7 at 45#6 at 45PC#7 at 31#7 at 40#6 at 38#6 at 22#7 at 30#7 at 38
  1. 182
  2. Concrete cover for reinforcement measured from the inside face of the wall shall not be less than ¾ inch (19.1 mm). Concrete cover for reinforcement measured from the outside face of the wall shall not be less than 1½ inches (38 mm) for No. 5 bars and smaller, and not less than 2 inches (51 mm) for larger bars.
  3. Concrete shall have a specified compressive strength, f1c of not less than 2,500 psi (17.2 MPa).
  4. The unfactored axial load per linear foot of wall shall not exceed 1.2t fc where t is the specified wall thickness in inches.

1807.1.6.2.1 Seismic requirements. Based on the seismic design category assigned to the structure in accordance with Section 1613, concrete foundation walls designed using Table 1807.1.6.2 shall be subject to the following limitations:

  1. Seismic Design Categories A and B. No additional seismic requirements, except provide reinforcement around openings in accordance with Section 1909.6.3.
  2. Seismic Design Categories C, D, E and F. Tables shall not be used except as allowed for plain concrete members in Section 1908.1.8.

1807.1.6.3 Masonry foundation walls. Masonry foundation walls shall comply with the following:

  1. The thickness shall comply with the requirements of Table 1807.1.6.3(1) for plain masonry walls or Table 1807.1.6.3(2), 1807.1.6.3(3) or 1807.1.6.3(4) for masonry walls with reinforcement.
  2. Vertical reinforcement shall have a minimum yield strength of 60,000 psi (414 MPa).
  3. The specified location of the reinforcement shall equal or exceed the effective depth distance, d, noted in Tables 1807.1.6.3(2), 1807.1.6.3(3) and 1807.1.6.3(4) and shall be measured from the face of the exterior (soil) side of the wall to the center of the vertical reinforcement. The reinforcement shall be placed within the tolerances specified in TMS 602/ACI 530.1/ASCE 6, Article 3.3.B.8 of the specified location.
  4. Grout shall comply with Section 2103.12.
  5. Concrete masonry units shall comply with ASTM C 90.
  6. Clay masonry units shall comply with ASTM C 652 for hollow brick, except compliance with ASTM C 62 or ASTM C 216 shall be permitted where solid masonry units are installed in accordance with Table 1807.1.6.3(1) for plain masonry.
TABLE 1807.1.6.3(1)
PLAIN MASONRY FOUNDATION WALLSa,b,c
MAXIMUM WALL HEIGHT (feet)MAXIMUM UNBALANCED BACKFILL HEIGHTe(feet)MINIMUM NOMINAL WALL THICKNESS (inches)
Design lateral soil loada (psf per foot of depth)
30145f60
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157kPa⁄m.
a. For design lateral soil loads, see Section 1610.
b. Provisions for this table are based on design and construction requirements specified in Section 1807.1.6.3.
c. Solid grouted hollow units or solid masonry units.
d. A design in compliance with Chapter 21 or reinforcement in accordance with Table 1807.1.6.3(2) is required.
e. For height of unbalanced backfill, see Section 1807.1.2.
f. Where unbalanced backfill height exceeds 8 feet and design lateral soil loads from Table 1610.1 are used, the requirements for 30 and 45 psf per foot of depth are not applicable (see Section 1610).
74(or less)888
581010
6101210 (solidc)
71210 (solidc)10 (solidc)
84(or less)888
581012
6101212 (solidc)
71212 (solidc)Note d
810 (solidc)12(solidc)Note d
94(or less)888
581012
610(solidc)12 (solidc)Note d
712 (solidc)12 (solidc)Note d
812(solidc)Note dNote d
9fNote dNote dNote d
183
  1. Masonry units shall be laid in running bond and installed with Type M or S mortar in accordance with Section 2103.8.
  2. The unfactored axial load per linear foot of wall shall not exceed 1.2 t f1m where t is the specified wall thickness in inches and f1m is the specified compressive strength of masonry in pounds per square inch.
  3. At least 4 inches (102 mm) of solid masonry shall be provided at girder supports at the top of hollow masonry unit foundation walls.
  4. Corbeling of masonry shall be in accordance with Section 2104.2. Where an 8-inch (203 mm) wall is corbeled, the top corbel shall not extend higher than the bottom of the floor framing and shall be a full course of headers at least 6 inches (152 mm) in length or the top course bed joint shall be tied to the vertical wall projection. The tie shall be W2.8 (4.8 mm) and spaced at a maximum horizontal distance of 36 inches (914 mm). The hollow space behind the corbelled masonry shall be filled with mortar or grout.

1807.1.6.3.1 Alternative foundation wall reinforcement. In lieu of the reinforcement provisions for masonry foundation walls in Table 1807.1.6.3(2), 1807.1.6.3(3) or 1807.1.6.3(4), alternative reinforcing bar sizes and spacings having an equivalent cross-sectional area of reinforcement per linear foot (mm) of wall shall be permitted to be used, provided the spacing of reinforcement does not exceed 72 inches (1829 mm) and reinforcing bar sizes do not exceed No. 11.

TABLE 1807.1.6.3(2)
8-INCH MASONRY FOUNDATION WALLS WITH REFINFORCEMENT WHERE d≥ 5 INCHESa,b,c
MAXIMUM WALL HEIGHT (feet-inches)MAXIMUM UNBALANCED BACKFILL HEIGHTd (feet-inches)MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (Inches)
Design lateral soil loada (psf per foot of depth)
30e45e60
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157 kpa/m.
a. For design lateral soil loads, see Section 1610.
b. Provisions for this table are based on design and construction requirements specified in Section 1807.1.6.3.
c. For alternative reinforcement, see Section 1807.1.6.3.1.
d. For height of unbalanced backfill, see Section 1807.1.2.
e. Where unbalanced backfill height exceeds 8 feet and design lateral soil loads from Table 1610.1 are used, the requirements for 30 and 45 psf per foot of depth are not applicable. See Section 1610.
7-44 (or less)#4 at 48#4 at 48#4 at 48
5-0#4 at 48#4 at 48#4 at 48
6-0#4 at 48#5 at 48#5 at 48
7-4#5 at 48#6 at 48#7 at 48
8-04 (or less)#4 at 48#4 at 48#4 at 48
5-0#4 at 48#4 at 48#4 at 48
6-0#4 at 48#5 at 48#5 at 48
7-0#5 at 48#6 at 48#7 at 48
8-0#5 at 48#6 at 48#7 at 48
8-84 (or less)#4 at 48#4 at 48#4 at 48
5-0#4 at 48#4 at 48#4 at 48
6-0#4 at 48#5 at 48#5 at 48
7-0#5 at 48#6 at 48#7 at 48
8-8e#6 at 48#7 at 48#8 at 48
9-44 (or less)#4 at 48#4 at 48#4 at 48
5-0#4 at 48#4 at 48#4 at 48
6-0#4 at 48#5 at 48#5 at 48
7-0#5 at 48#6 at 48#7 at 48
8-0#6 at 48#7 at 48#8 at 48
9-4e#7 at 48#8 at 48#9 at 48
10-04 (or less)#4 at 48#4 at 48#4 at 48
5-0#4 at 48#4 at 48#4 at 48
6-0#4 at 48#5 at 48#5 at 48
7-0#5 at 48#6 at 48#7 at 48
8-0#6 at 48#7 at 48#8 at 48
9-0#7 at 48#8 at 48#9 at 48
10-0e#7 at 48#9 at 48#9 at 48
184

1807.1.6.3.2 Seismic requirements. Based on the seismic design category assigned to the structure in accordance with Section 1613, masonry foundation walls designed using Tables 1807.1.6.3(1) through 1807.1.6.3(4) shall be subject to the following limitations:

  1. Seismic Design Categories A and B. No additional seismic requirements.
  2. Seismic Design Category C. A design using Tables 1807.1.6.3(1) through 1807.1.6.3(4) is subject to the seismic requirements of Section 1.17.4.3 of TMS 402/ACI 530/ASCE 5.
  3. Seismic Design Category D. A design using Tables 1807.1.6.3(2) through 1807.1.6.3(4) is subject to the seismic requirements of Section 1.17.4.4 of TMS 402/ACI 530/ASCE 5.
  4. Seismic Design Categories E and F. A design using Tables 1807.1.6.3(2) through 1807.1.6.3(4) is subject to the seismic requirements of Section 1.17.4.5 of TMS 402/ACI 530/ASCE 5.

1807.2 Retaining walls. Retaining walls shall be designed in accordance with Sections 1807.2.1 through 1807.2.3.

1807.2.1 General. Retaining walls shall be designed to ensure stability against overturning, sliding, excessive foundation pressure and water uplift. Where a keyway is extended below the wall base with the intent to engage passive pressure and enhance sliding stability, lateral soil pressures on both

TABLE 1807.1.6.3(3)
10-INCH MASONRY FOUNDATION WALLS WITH REFINFORCEMENT WHERE d≥ 6.75 INCHESa,b,c
MAXIMUM WALL HEIGHT (feet-inches)MAXIMUM UNBALANCED BACKFILL HEIGHTd (feet-inches)MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (Inches)
Design lateral soil loada(psf per foot of depth)
30e45e60
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157 kpa/m.
a. For design lateral soil loads, see Section 1610.
b. Provisions for this table are based on design and construction requirements specified in Section 1807.1.6.3.
c. For alternative reinforcement, see Section 1807.1.6.3.1.
d. For height of unbalanced backfill, see Section 1807.1.2.
e. Where unbalanced backfill height exceeds 8 feet and design lateral soil loads from Table 1610.1 are used, the requirements for 30 and 45 psf per foot of depth are
not applicable. See Section 1610.
7-44 (or less)#4 at 56#4 at 56#4 at 56
5-0#4 at 56#4 at 56#4 at 56
6-0#4 at 56#4 at 56#5 at 56
7-4#4 at 56#5 at 56#6 at 56
8-04 (or less)#4 at 56#4 at 56#4 at 56
5-0#4 at 56#4 at 56#4 at 56
6-0#4 at 56#4 at 56#5 at 56
7-0#4 at 56#5 at 56#6 at 56
8-0#5 at 56#6 at 56#7 at 56
8-84 (or less)#4 at 56#4 at 56#4 at 56
5-0#4 at 56#4 at 56#4 at 56
6-0#4 at 56#4 at 56#5 at 56
7-0#4 at 56#5 at 56#6 at 56
8-8c#5 at 56#7 at 56#8 at 56
9-44 (or less)#4 at 56#4 at 56#4 at 56
5-0#4 at 56#4 at 56#4 at 56
6-0#4 at 56#4 at 56#5 at 56
7-0#4 at 56#5 at 56#6 at 56
8-0#5 at 56#6 at 56#7 at 56
9-4e#6 at 56#7 at 56#8 at 56
10-04 (or less)#4 at 56#4 at 56#4 at 56
5-0#4 at 56#4 at 56#4 at 56
6-0#4 at 56#4 at 56#5 at 56
7-0#5 at 56#6 at 56#7 at 56
8-0#5 at 56#7 at 56#8 at 56
9-0e#6 at 56#7 at 56#9 at 56
10-0e#7 at 56#8 at 56#9 at 56
185

sides of the keyway shall be considered in the sliding analysis.

1807.2.2 Design lateral soil loads. Retaining walls shall be designed for the lateral soil loads set forth in Section 1610.

1807.2.3 Safety factor. Retaining walls shall be designed to resist the lateral action of soil to produce sliding and over-turning with a minimum safety factor of 1.5 in each case. The load combinations of Section 1605 shall not apply to this requirement. Instead, design shall be based on 0.7 times nominal earthquake loads, 1.0 times other nominal loads, and investigation with one or more of the variable loads set to zero. The safety factor against lateral sliding shall be taken as the available soil resistance at the base of the retaining wall foundation divided by the net lateral force applied to the retaining wall.

Exception: Where earthquake loads are included, the minimum safety factor for retaining wall sliding and overturning shall be 1.1.

1807.3 Embedded posts and poles. Designs to resist both axial and lateral loads employing posts or poles as columns embedded in earth or in concrete footings in earth shall be in accordance with Sections 1807.3.1 through 1807.3.3.

1807.3.1 Limitations. The design procedures outlined in this section are subject to the following limitations:

  1. The frictional resistance for structural walls and slabs on silts and clays shall be limited to one-half of the normal force imposed on the soil by the weight of the footing or slab.
  2. Posts embedded in earth shall not be used to provide lateral support for structural or nonstructural materials such as plaster, masonry or concrete unless bracing is provided that develops the limited deflection required.
TABLE 1807.1.6.3(4)
12-INCH MASONRY FOUNDATION WALLS WITH REFINFORCEMENT WHERE d≥ 8.75 INCHESa,b,c
MAXIMUM WALL HEIGHT (feet-inches)MAXIMUM UNBALANCED BACKFILL HEIGHTd (feet-inches)MINIMUM VERTICAL REINFORCEMENT-BAR SIZE AND SPACING (Inches)
Design lateral soil loada(psf per foot of depth)
30e45e60
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot per foot = 0.157 kpa/m.
a. For design lateral soil loads, see Section 1610.,
b. Provisions for this table are based on design and construction requirements specified in Section 1807.1.6.3.
c. For alternative reinforcement, see Section 1807.1.6.3.1.
d. For height of unbalanced backfill, see Section 1807.1.2.
e. Where unbalanced backfill height exceeds 8 feet and design lateral soil loads from Table 1610.1 are used, the requirements for 30 and 45 psf per foot of depth are not applicable. See Section 1610.
7-44 (or less)#4 at 72#4 at 72#4 at 72
5-0#4 at 72#4 at 72#4 at 72
6-0#4 at 72#4 at 72#5 at 72
7-4#4 at 72#5 at 72#6 at 72
8-04 (or less)#4 at 72#4 at 72#4 at 72
5-0#4 at 72#4 at 72#4 at 72
6-0#4 at 72#4 at 72#5 at 72
7-0#4 at 72#5 at 72#6 at 72
8-0#5 at 72#6 at 72#7 at 72
8-84 (or less)#4 at 72#4 at 72#4 at 72
5-0#4 at 72#4 at 72#4 at 72
6-0#4 at 72#4 at 72#5 at 72
7-0#4 at 72#5 at 72#6 at 72
8-8c#5 at 72#7 at 72#8 at 72
9-44 (or less)#4 at 72#4 at 72#4 at 72
5-0#4 at 72#4 at 72#4 at 72
6-0#4 at 72#4 at 72#5 at 72
7-0#4 at 72#5 at 72#6 at 72
8-0#5 at 72#6 at 72#7 at 72
9-4e#6 at 72#7 at 72#8 at 72
10-04 (or less)#4 at 72#4 at 72#4 at 72
5-0#4 at 72#4 at 72#4 at 72
6-0#4 at 72#4 at 72#5 at 72
7-0#5 at 72#6 at 72#7 at 72
8-0#5 at 72#7 at 72#8 at 72
9-0e#6 at 72#7 at 72#9 at 72
10-0e#7 at 72#8 at 72#9 at 72
186

Wood poles shall be treated in accordance with AWPA U1 for sawn timber posts (commodity Specification A, Use Category 4B) and for round timber posts (Commodity Specification B, Use Category 4B).

1807.3.2 Design criteria. The depth to resist lateral loads shall be determined using the design criteria established in Sections 1807.3.2.1 through 1807.3.2.3, or by other methods approved by the building official.

1807.3.2.1 Nonconstrained. The following formula shall be used in determining the depth of embedment required to resist lateral loads where no lateral constraint is provided at the ground surface, such as by a rigid floor or rigid ground surface pavement, and where no lateral constraint is provided above the ground surface, such as by a structural diaphragm.

Image

where:

A = 2.34P/S1b.

b = Diameter of round post or footing or diagonal dimension of square post or footing, feet (m).

d = Depth of embedment in earth in feet (m) but not over 12 feet (3658 mm) for purpose of computing lateral pressure.

h = Distance in feet (m) from ground surface to point of application of “P.”

P = Applied lateral force in pounds (kN).

S1 = Allowable lateral soil-bearing pressure as set forth in Section 1806.2 based on a depth of one-third the depth of embedment in pounds per square foot (psf) (kPa).

1807.3.2.2 Constrained. The following formula shall be used to determine the depth of embedment required to resist lateral loads where lateral constraint is provided at the ground surface, such as by a rigid floor or pavement.

Image

or alternatively

Image

where:

Mg = Moment in the post at grade, in foot-pounds (kN-m).

S3 = Allowable lateral soil-bearing pressure as set forth in Section 1806.2 based on a depth equal to the depth of embedment in pounds per square foot (kPa).

1807.3.2.3 Vertical load. The resistance to vertical loads shall be determined using the vertical foundation pressure set forth in Table 1806.2.

1807.3.3 Backfill. The backfill in the annular space around columns not embedded in poured footings shall be by one of the following methods:

  1. Backfill shall be of concrete with a specified compressive strength of not less than 2,000 psi (13.8 MPa). The hole shall not be less than 4 inches (102 mm) larger than the diameter of the column at its bottom or 4 inches (102 mm) larger than the diagonal dimension of a square or rectangular column.
  2. Backfill shall be of clean sand. The sand shall be thoroughly compacted by tamping in layers not more than 8 inches (203 mm) in depth.
  3. Backfill shall be of controlled low-strength material (CLSM).

SECTION 1808
FOUNDATIONS

1808.1 General. Foundations shall be designed and constructed in accordance with Sections 1808.2 through 1808.9. Shallow foundations shall also satisfy the requirements of Section 1809. Deep foundations shall also satisfy the requirements of Section 1810.

1808.2 Design for capacity and settlement. Foundations shall be so designed that the allowable bearing capacity of the soil is not exceeded, and that differential settlement is minimized. Foundations in areas with expansive soils shall be designed in accordance with the provisions of Section 1808.6.

1808.3 Design loads. Foundations shall be designed for the most unfavorable effects due to the combinations of loads specified in Section 1605.2 or 1605.3. The dead load is permitted to include the weight of foundations and overlying fill. Reduced live loads, as specified in Sections 1607.9 and 1607.11, shall be permitted to be used in the design of foundations.

1808.3.1 Seismic overturning. Where foundations are proportioned using the load combinations of Section 1605.2 or 1605.3.1, and the computation of seismic overturning effects is by equivalent lateral force analysis or modal analysis, the proportioning shall be in accordance with Section 12.13.4 of ASCE 7.

1808.4 Vibratory loads. Where machinery operations or other vibrations are transmitted through the foundation, consideration shall be given in the foundation design to prevent detrimental disturbances of the soil.

1808.5 Shifting or moving soils. Where it is known that the shallow subsoils are of a shifting or moving character, foundations shall be carried to a sufficient depth to ensure stability.

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1808.6 Design for expansive soils. Foundations for buildings and structures founded on expansive soils shall be designed in accordance with Section 1808.6.1 or 1808.6.2.

Exception: Foundation design need not comply with Section 1808.6.1 or 1808.6.2 where one of the following conditions is satisfied:

  1. The soil is removed in accordance with Section 1808.6.3; or
  2. The building official approves stabilization of the soil in accordance with Section 1808.6.4.

1808.6.1 Foundations. Foundations placed on or within the active zone of expansive soils shall be designed to resist differential volume changes and to prevent structural damage to the supported structure. Deflection and racking of the supported structure shall be limited to that which will not interfere with the usability and serviceability of the structure.

Foundations placed below where volume change occurs or below expansive soil shall comply with the following provisions:

  1. Foundations extending into or penetrating expansive soils shall be designed to prevent uplift of the supported structure.
  2. Foundations penetrating expansive soils shall be designed to resist forces exerted on the foundation due to soil volume changes or shall be isolated from the expansive soil.

1808.6.2 Slab-on-ground foundations. Moments, shears and deflections for use in designing slab-on-ground, mat or raft foundations on expansive soils shall be determined in accordance with WRI/CRSI Design of Slab-on-Ground Foundations or PTI Standard Requirements for Analysis of Shallow Concrete Foundations on Expansive Soils. Using the moments, shears and deflections determined above, nonprestressed slabs-on-ground, mat or raft foundations on expansive soils shall be designed in accordance with WRI/CRSI Design of Slab-on-Ground Foundations and post-tensioned slab-on-ground, mat or raft foundations on expansive soils shall be designed in accordance with PTI Standard Requirements for Design of Shallow Post-Tensioned Concrete Foundations on Expansive Soils. It shall be permitted to analyze and design such slabs by other methods that account for soil-structure interaction, the deformed shape of the soil support, the plate or stiffened plate action of the slab as well as both center lift and edge lift conditions. Such alternative methods shall be rational and the basis for all aspects and parameters of the method shall be available for peer review.

1808.6.3 Removal of expansive soil. Where expansive soil is removed in lieu of designing foundations in accordance with Section 1808.6.1 or 1808.6.2, the soil shall be removed to a depth sufficient to ensure a constant moisture content in the remaining soil. Fill material shall not contain expansive soils and shall comply with Section 1804.5 or 1804.6.

Exception: Expansive soil need not be removed to the depth of constant moisture, provided the confining pressure in the expansive soil created by the fill and supported structure exceeds the swell pressure.

1808.6.4 Stabilization. Where the active zone of expansive soils is stabilized in lieu of designing foundations in accordance with Section 1808.6.1 or 1808.6.2, the soil shall be stabilized by chemical, dewatering, presaturation or equivalent techniques.

1808.7 Foundations on or adjacent to slopes. The placement of buildings and structures on or adjacent to slopes steeper than one unit vertical in three units horizontal (33.3-percent slope) shall comply with Sections 1808.7.1 through 1808.7.5.

1808.7.1 Building clearance from ascending slopes. In general, buildings below slopes shall be set a sufficient distance from the slope to provide protection from slope drainage, erosion and shallow failures. Except as provided in Section 1808.7.5 and Figure 1808.7.1, the following criteria will be assumed to provide this protection. Where the existing slope is steeper than one unit vertical in one unit horizontal (100-percent slope), the toe of the slope shall be assumed to be at the intersection of a horizontal plane drawn from the top of the foundation and a plane drawn tangent to the slope at an angle of 45 degrees (0.79 rad) to the horizontal. Where a retaining wall is constructed at the toe of the slope, the height of the slope shall be measured from the top of the wall to the top of the slope.

FIGURE 1808.7.1FOUNDATION CLEARANCES FROM SLOPES

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1808.7.2 Foundation setback from descending slope surface. Foundations on or adjacent to slope surfaces shall be founded in firm material with an embedment and set back from the slope surface sufficient to provide vertical and lateral support for the foundation without detrimental settlement. Except as provided for in Section 1808.7.5 and Figure 1808.7.1, the following setback is deemed adequate to meet the criteria. Where the slope is steeper than 1 unit vertical in 1 unit horizontal (100-percent slope), the required setback shall be measured from an imaginary plane 45 degrees (0.79 rad) to the horizontal, projected upward from the toe of the slope.

1808.7.3 Pools. The setback between pools regulated by this code and slopes shall be equal to one-half the building footing setback distance required by this section. That portion of the pool wall within a horizontal distance of 7 feet (2134 mm) from the top of the slope shall be capable of supporting the water in the pool without soil support.

1808.7.4 Foundation elevation. On graded sites, the top of any exterior foundation shall extend above the elevation of the street gutter at point of discharge or the inlet of an approved drainage device a minimum of 12 inches (305 mm) plus 2 percent. Alternate elevations are permitted subject to the approval of the building official, provided it can be demonstrated that required drainage to the point of discharge and away from the structure is provided at all locations on the site.

1808.7.5 Alternate setback and clearance. Alternate setbacks and clearances are permitted, subject to the approval of the building official. The building official shall be permitted to require a geotechnical investigation as set forth in Section 1803.5.10.

1808.8 Concrete foundations. The design, materials and construction of concrete foundations shall comply with Sections 1808.8.1 through 1808.8.6 and the provisions of Chapter 19.

Exception: Where concrete footings supporting walls of light-frame construction are designed in accordance with Table 1809.7, a specific design in accordance with Chapter 19 is not required.

1808.8.1 Concrete or grout strength and mix proportioning. Concrete or grout in foundations shall have a specified compressive strength (f′c) not less than the largest applicable value indicated in Table 1808.8.1.

Where concrete is placed through a funnel hopper at the top of a deep foundation element, the concrete mix shall be designed and proportioned so as to produce a cohesive workable mix having a slump of not less than 4 inches (102 mm) and not more than 8 inches (204 mm). Where concrete or grout is to be pumped, the mix design including slump shall be adjusted to produce a pumpable mixture.

1808.8.2 Concrete cover. The concrete cover provided for prestressed and nonprestressed reinforcement in foundations shall be no less than the largest applicable value specified in Table 1808.8.2. Longitudinal bars spaced less than 1½ inches (38 mm) clear distance apart shall be considered bundled bars for which the concrete cover provided shall also be no less than that required by Section 7.7.4 of ACI 318. Concrete cover shall be measured from the concrete surface to the outermost surface of the steel to which the cover requirement applies. Where concrete is placed in a temporary or permanent casing or a mandrel, the inside face of the casing or mandrel shall be considered the concrete surface.

1808.8.3 Placement of concrete. Concrete shall be placed in such a manner as to ensure the exclusion of any foreign matter and to secure a full-size foundation. Concrete shall not be placed through water unless a tremie or other method approved by the building official is used. Where placed under or in the presence of water, the concrete shall be deposited by approved means to ensure minimum segregation of the mix and negligible turbulence of the water. Where depositing concrete from the top of a deep foundation element, the concrete shall be chuted directly into smooth-sided pipes or tubes or placed in a rapid and continuous operation through a funnel hopper centered at the top of the element.

1808.8.4 Protection of concrete. Concrete foundations shall be protected from freezing during depositing and for a period of not less than five days thereafter. Water shall not be allowed to flow through the deposited concrete.

1808.8.5 Forming of concrete. Concrete foundations are permitted to be cast against the earth where, in the opinion of the building official, soil conditions do not require formwork. Where formwork is required, it shall be in accordance with Chapter 6 of ACI 318.

1808.8.6 Seismic requirements. See Section 1908 for additional requirements for foundations of structures assigned to Seismic Design Category C, D, E or F.

For structures assigned to Seismic Design Category D, E or F, provisions of ACI 318, Sections 21.12.1 through 21.12.4, shall apply where not in conflict with the provisions of Sections 1808 through 1810.

Exceptions:

  1. Detached one- and two-family dwellings of light-frame construction and two stories or less above grade plane are not required to comply with the provisions of ACI 318, Sections 21.12.1 through 21.12.4.
  2. Section 21.12.4.4(a) of ACI 318 shall not apply.

1808.9 Vertical masonry foundation elements. Vertical masonry foundation elements that are not foundation piers as defined in Section 2102.1 shall be designed as piers, walls or columns, as applicable, in accordance with TMS 402/ACI 530/ASCE 5.

SECTION 1809
SHALLOW FOUNDATIONS

1809.1 General. Shallow foundations shall be designed and constructed in accordance with Sections 1809.2 through 1809.13.

1809.2 Supporting soils. Shallow foundations shall be built on undisturbed soil, compacted fill material or controlled low-strength material (CLSM). Compacted fill material shall be placed in accordance with Section 1804.5. CLSM shall be placed in accordance with Section 1804.6.

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TABLE 1808.8.1
MINIMUM SPECIFIED COMPRESSIVE STRENGTH f′c OF CONCRETE OR GROUT
FOUNDATION ELEMENT OR CONDITIONSPECIFIED COMPRESSIVE
STRENGTH, f′c
For SI: 1 pound per square inch = 0.00689 MPa.
1. Foundations for structures assigned to Seismic Design Category A, B or C2,500 psi
2a. Foundations for Group R or U occupancies of light-frame construction, two stories or less in height, assigned to Seismic Design Category D, E or F2,500 psi
2b. Foundations for other structures assigned to Seismic Design Category D, E or F3,000 psi
3. Precast nonprestressed drived piles4,000 psi
4. Socketed drilled shafts4,000 psi
5. Micropiles4,000 psi
6. Precast prestressed driven piles5,000 psi
TABLE 1808.8.2
MINIMUM CONCRETE COVER
FOUNDATION ELEMENT OR CONDITIONMINIMUM COVER
For SI: 1 inch = 25.4 mm.
1. Shallow foundationsIn accordance with Section 7.7 of ACI 318
2. Precast nonprestressed deep foundation elements 
Exposed to seawater3 inches
Not manufactured under plant conditions2 inches
Manufactured under plant control conditionsIn accordance with Section 7.7.3 of ACI 318
3. Precast prestressed deep foundation elements 
Exposed to seawater2.5 inches
OtherIn accordance with Section 7.7.3 of ACI 318
4. Cast-in-place deep foundation elements not enclosed by a steel pipe, tube or permanent casing2.5 inches
5. Cast-in-place deep foundation elements enclosed by a steel pipe, tube or permanent casing1 inch
6. Structural steel core within a steel pipe, tube or permanent casing2 inches
7. Cast-in-place drilled shafts enclosed by a stable rock socket1.5 inches
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1809.3 Stepped footings. The top surface of footings shall be level. The bottom surface of footings shall be permitted to have a slope not exceeding one unit vertical in 10 units horizontal (10-percent slope). Footings shall be stepped where it is necessary to change the elevation of the top surface of the footing or where the surface of the ground slopes more than one unit vertical in 10 units horizontal (10-percent slope).

1809.4 Depth and width of footings. The minimum depth of footings below the undisturbed ground surface shall be 12 inches (305 mm). Where applicable, the requirements of Section 1809.5 shall also be satisfied. The minimum width of footings shall be 12 inches (305 mm).

1809.5 Frost protection. Except where otherwise protected from frost, foundations and other permanent supports of buildings and structures shall be protected from frost by one or more of the following methods:

  1. Extending below the frost line of the locality;
  2. Constructing in accordance with ASCE 32; or
  3. Erecting on solid rock.

Exception: Free-standing buildings meeting all of the following conditions shall not be required to be protected:

  1. Assigned to Occupancy Category I, in accordance with Section 1604.5;
  2. Area of 600 square feet (56 m2) or less for light-frame construction or 400 square feet (37 m2) or less for other than light-frame construction; and
  3. Eave height of 10 feet (3048 mm) or less.

Shallow foundations shall not bear on frozen soil unless such frozen condition is of a permanent character.

1809.6 Location of footings. Footings on granular soil shall be so located that the line drawn between the lower edges of adjoining footings shall not have a slope steeper than 30 degrees (0.52 rad) with the horizontal, unless the material supporting the higher footing is braced or retained or otherwise laterally supported in an approved manner or a greater slope has been properly established by engineering analysis.

1809.7 Prescriptive footings for light-frame construction. Where a specific design is not provided, concrete or masonry-unit footings supporting walls of light-frame construction shall be permitted to be designed in accordance with Table 1809.7.

1809.8 Plain concrete footings. The edge thickness of plain concrete footings supporting walls of other than light-frame construction shall not be less than 8 inches (203 mm) where placed on soil or rock.

Exception: For plain concrete footings supporting Group R-3 occupancies, the edge thickness is permitted to be 6 inches (152 mm), provided that the footing does not extend beyond a distance greater than the thickness of the footing on either side of the supported wall.

TABLE 1809.7
PRESCRIPTIVE FOOTINGS SUPPORTING WALLS OF
LIGHT-FRAME CONSTRUCTIONa, b, c, d, e
NUMBER OF FLOORS SUPPORTED BY THE FOOTINGfWIDTH OF FOOTING (inches)THICKNESS OF FOOTING (inches)
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a. Depth of footings shall be in accordance with Section 1809.4
b. The ground under the floor shall be permitted to be excavated to the elevation of the top of the footing.
c. Interior stud-bearing walls shall be permitted to be supported by isolated footings. The footing width and length shall be twice the width shown in this table, and footings shall be spaced not more than 6 feet on center.
d. See Section 1908 for additional requirements for concrete footings of structures assigned to Seismic Design Category C, D, E or F.
e. For thickness of foundation walls, see Section 1807.1.6.
f. Footings shall be permitted to support a roof in addition to the stipulated number of floors. Footings supporting roof only shall be as required for supporting one floor.
g. Plain concrete footings for Group R-3 occupancies shall be permitted to be 6 inches thick.
1126
2156
3188g

1809.9 Masonry-unit footings. The design, materials and construction of masonry-unit footings shall comply with Sections 1809.9.1 and 1809.9.2, and the provisions of Chapter 21.

Exception: Where a specific design is not provided, masonry-unit footings supporting walls of light-frame construction shall be permitted to be designed in accordance with Table 1809.7.

1809.9.1 Dimensions. Mansonry-unit footings shall be laid in Type M or S mortar complying with Section 2103.8 and the depth shall not be less than twice the projection beyond the wall, pier or column. The width shall not be less than 8 inches (203 mm) wider than the wall supported thereon.

1809.9.2 Offsets. The maximum offset of each course in brick foundation walls stepped up from the footings shall be 1½ inches (38 mm) where laid in single courses, and 3 inches (76 mm) where laid in double courses.

1809.10 Pier and curtain wall foundations. Except in Seismic Design Categories D, E and F, pier and curtain wall foundations shall be permitted to be used to support light-frame construction not more than two stories above grade plane, provided the following requirements are met:

  1. All load-bearing walls shall be placed on continuous concrete footings bonded integrally with the exterior wall footings.
  2. The minimum actual thickness of a load-bearing masonry wall shall not be less than 4 inches (102 mm) nominal or 3 5/8 inches (92 mm) actual thickness, and shall be bonded integrally with piers spaced 6 feet (1829 mm) on center (o.c.).191
  3. Piers shall be constructed in accordance with Chapter 21 and the following:
    1. The unsupported height of the masonry piers shall not exceed 10 times their least dimension.
    2. Where structural clay tile or hollow concrete masonry units are used for piers supporting beams and girders, the cellular spaces shall be filled solidly with concrete or Type M or S mortar.

      Exception: Unfilled hollow piers shall be permitted where the unsupported height of the pier is not more than four times its least dimension.

    3. Hollow piers shall be capped with 4 inches (102 mm) of solid masonry or concrete or the cavities of the top course shall be filled with concrete or grout.
  4. The maximum height of a 4-inch (102 mm) load-bearing masonry foundation wall supporting wood frame walls and floors shall not be more than 4 feet (1219 mm) in height.
  5. The unbalanced fill for 4-inch (102 mm) foundation walls shall not exceed 24 inches (610 mm) for solid masonry, nor 12 inches (305 mm) for hollow masonry.

1809.11 Steel grillage footings. Grillage footings of structural steel shapes shall be separated with approved steel spacers and be entirely encased in concrete with at least 6 inches (152 mm) on the bottom and at least 4 inches (102 mm) at all other points. The spaces between the shapes shall be completely filled with concrete or cement grout.

1809.12 Timber footings. Timber footings shall be permitted for buildings of Type V construction and as otherwise approved by the building official. Such footings shall be treated in accordance with AWPA U1 (Commodity Specification A, Use Category 4B). Treated timbers are not required where placed entirely below permanent water level, or where used as capping for wood piles that project above the water level over submerged or marsh lands. The compressive stresses perpendicular to grain in untreated timber footings supported upon treated piles shall not exceed 70 percent of the allowable stresses for the species and grade of timber as specified in the AF&PA NDS.

1809.13 Footing seismic ties. Where a structure is assigned to Seismic Design Category D, E or F in accordance with Section 1613, individual spread footings founded on soil defined in Section 1613.5.2 as Site Class E or F shall be interconnected by ties. Unless it is demonstrated that equivalent restraint is provided by reinforced concrete beams within slabs on grade or reinforced concrete slabs on grade, ties shall be capable of carrying, in tension or compression, a force equal to the lesser of the product of the larger footing design gravity load times the seismic coefficient, SDS, divided by 10 and 25 percent of the smaller footing design gravity load.

SECTION 1810
DEEP FOUNDATIONS

1810.1 General. Deep foundations shall be analyzed, designed, detailed and installed in accordance with Sections 1810.1 through 1810.4.

1810.1.1 Geotechnical investigation. Deep foundations shall be designed and installed on the basis of a geotechnical investigation as set forth in Section 1803.

1810.1.2 Use of existing deep foundation elements. Deep foundation elements left in place where a structure has been demolished shall not be used for the support of new construction unless satisfactory evidence is submitted to the building official, which indicates that the elements are sound and meet the requirements of this code. Such elements shall be load tested or redriven to verify their capacities. The design load applied to such elements shall be the lowest allowable load as determined by tests or redriving data.

1810.1.3 Deep foundation elements classified as columns. Deep foundation elements standing unbraced in air, water or fluid soils shall be classified as columns and designed as such in accordance with the provisions of this code from their top down to the point where adequate lateral support is provided in accordance with Section 1810.2.1.

Exception: Where the unsupported height to least horizontal dimension of a cast-in-place deep foundation elements does not exceed three, it shall be permitted to design and construct such an element as a pedestal in accordance with ACI 318.

1810.1.4 Special types of deep foundations. The use of types of deep foundation elements not specifically mentioned herein is permitted, subject to the approval of the building official, upon the submission of acceptable test data, calculations and other information relating to the structural properties and load capacity of such elements. The allowable stresses for materials shall not in any case exceed the limitations specified herein.

1810.2 Analysis. The analysis of deep foundations for design shall be in accordance with Sections 1810.2.1 through 1810.2.5.

1810.2.1 Lateral support. Any soil other than fluid soil shall be deemed to afford sufficient lateral support to prevent buckling of deep foundation elements and to permit the design of the elements in accordance with accepted engineering practice and the applicable provisions of this code.

Where deep foundation elements stand unbraced in air, water or fluid soils, it shall be permitted to consider them laterally supported at a point 5 feet (1524 mm) into stiff soil or 10 feet (3048 mm) into soft soil unless otherwise approved by the building official on the basis of a geotechnical investigation by a registered design professional.

1810.2.2 Stability. Deep foundation elements shall be braced to provide lateral stability in all directions. Three or more elements connected by a rigid cap shall be considered braced, provided that the elements are located in radial directions from the centroid of the group not less than 60

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degrees (1 rad) apart. A two-element group in a rigid cap shall be considered to be braced along the axis connecting the two elements. Methods used to brace deep foundation elements shall be subject to the approval of the building official.

Deep foundation elements supporting walls shall be placed alternately in lines spaced at least 1 foot (305 mm) apart and located symmetrically under the center of gravity of the wall load carried, unless effective measures are taken to provide for eccentricity and lateral forces, or the foundation elements are adequately braced to provide for lateral stability.

Exceptions:

  1. Isolated cast-in-place deep foundation elements without lateral bracing shall be permitted where the least horizontal dimension is no less than 2 feet (610 mm), adequate lateral support in accordance with Section 1810.2.1 is provided for the entire height and the height does not exceed 12 times the least horizontal dimension.
  2. A single row of deep foundation elements without lateral bracing is permitted for one- and two-family dwellings and lightweight construction not exceeding two stories above grade plane or 35 feet (10 668 mm) in building height, provided the centers of the elements are located within the width of the supported wall.

1810.2.3 Settlement. The settlement of a single deep foundation element or group thereof shall be estimated based on approved methods of analysis. The predicted settlement shall cause neither harmful distortion of, nor instability in, the structure, nor cause any element to be loaded beyond its capacity.

1810.2.4 Lateral loads. The moments, shears and lateral deflections used for design of deep foundation elements shall be established considering the nonlinear interaction of the shaft and soil, as determined by a registered design professional. Where the ratio of the depth of embedment of the element to its least horizontal dimension is less than or equal to six, it shall be permitted to assume the element is rigid.

1810.2.4.1 Seismic Design Categories D through F. For structures assigned to Seismic Design Category D, E or F, deep foundation elements on Site Class E or F sites, as determined in Section 1613.5.2, shall be designed and constructed to withstand maximum imposed curvatures from earthquake ground motions and structure response. Curvatures shall include free-field soil strains modified for soil-foundation-structure interaction coupled with foundation element deformations associated with earthquake loads imparted to the foundation by the structure.

Exception: Deep foundation elements that satisfy the following additional detailing requirements shall be deemed to comply with the curvature capacity requirements of this section.

  1. Precast prestressed concrete piles detailed in accordance with Section 1810.3.8.3.3.
  2. Cast-in-place deep foundation elements with a minimum longitudinal reinforcement ratio of 0.005 extending the full length of the element and detailed in accordance with Sections 21.6.4.2, 21.6.4.3 and 21.6.4.4 of ACI 318 as required by Section 1810.3.9.4.2.2.

1810.2.5 Group effects. The analysis shall include group effects on lateral behavior where the center-to-center spacing of deep foundation elements in the direction of lateral force is less than eight times the least horizontal dimension of an element. The analysis shall include group effects on axial behavior where the center-to-center spacing of deep foundation elements is less than three times the least horizontal dimension of an element.

1810.3 Design and detailing. Deep foundations shall be designed and detailed in accordance with Sections 1810.3.1 through 1810.3.12.

1810.3.1 Design conditions. Design of deep foundations shall include the design conditions specified in Sections 1810.3.1.1 through 1810.3.1.6, as applicable.

1810.3.1.1 Design methods for concrete elements. Where concrete deep foundations are laterally supported in accordance with Section 1810.2.1 for the entire height and applied forces cause bending moments no greater than those resulting from accidental eccentricities, structural design of the element using the load combinations of Section 1605.3 and the allowable stresses specified in this chapter shall be permitted. Otherwise, the structural design of concrete deep foundation elements shall use the load combinations of Section 1605.2 and approved strength design methods.

1810.3.1.2 Composite elements. Where a single deep foundation element comprises two or more sections of different materials or different types spliced together, each section of the composite assembly shall satisfy the applicable requirements of this code, and the maximum allowable load in each section shall be limited by the structural capacity of that section.

1810.3.1.3 Mislocation. The foundation or superstructure shall be designed to resist the effects of the mislocation of any deep foundation element by no less than 3 inches (76 mm). To resist the effects of mislocation, compressive overload of deep foundation elements to 110 percent of the allowable design load shall be permitted.

1810.3.1.4 Driven piles. Driven piles shall be designed and manufactured in accordance with accepted engineering practice to resist all stresses induced by handling, driving and service loads.

1810.3.1.5 Helical piles. Helical piles shall be designed and manufactured in accordance with accepted engineering practice to resist all stresses induced by installation into the ground and service loads.

1810.3.1.5.1 Helical Piles Seismic Requirements. [OSHPD 2] For structures assigned to Seismic Design Category D, E or F, capacities of helical piles shall be determined in accordance with Section

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1810.3.3 by at least two project specific preproduction tests for each soil profile, size and depth of helical pile. At least two percent of all production piles shall be proof tested to design ultimate strength determined by using load combinations in Section 1605.2.1.

Helical piles shall satisfy corrosion resistance requirements of ICC-ES AC 358. In addition, all helical pile materials that are