Chapter 16 — STRUCTURAL DESIGN

(Matrix Adoption Tables are nonregulatory, intended only as an aid to the code user.

See Chapter 1 for state agency authority and building applications.)

The state agency does not adopt sections identified with the following symbol: The Office of the State Fire Marshal’s adoption of this chapter or individual sections is applicable to structures regulated by other state agencies pursuant to Section 1.11.

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

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2 2019 CALIFORNIA BUILDING CODE Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. ANY UNAUTHORIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT, AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.

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CHAPTER 16

STRUCTURAL DESIGN

User notes:

About this chapter: Chapter 16 establishes minimum design requirements so that the structural components of buildings are proportioned to resist the loads that are likely to be encountered. In addition, this chapter assigns buildings and structures to risk categories that are indicative of their intended use. The loads specified herein along with the required load combinations have been established through research and ser- vice performance of buildings and structures. The application of these loads and adherence to the serviceability criteria enhances the protec- tion of life and property.

Code development reminder: Code change proposals to this chapter will be considered by the IBC—Structural Code Development Commit- tee during the 2019 (Group B) Code Development Cycle. See explanation on page ix.

1601.1.4 Amendments. [DSA-SS/CC, OSHPD]

1. [OSHPD 1R, 2 & 5] In addition to the amendments in this chapter, these buildings shall comply with the requirements of Sections 1617A.1.1, 1617A.1.4, 1617A.1.18 - 1617A.1.20, 1617A.1.27, 1617A.1.39 and 1617A.1.41.

2. [DSA-SS/CC] See Section 1617 for additional requirements.

OSHPD 1R, 2 & 5] In addition to requirements of the Cali- fornia Administrative Code and the California Building Code, any aspect of project design, construction, quality assurance or quality control programs for which this code requires approval by the Registered Design Professional (RDP), are also subject to approval by the enforcement agency.

and resistance factor design. Where strength design or load and resistance factor design is used, buildings and other structures, and portions thereof, shall be designed to resist the most critical effects resulting from the following combinations of factored loads:

1.4( D + F ) (Equation 16-1)

1.2( D + F ) + 1.6( L + H ) + 0.5( Lr or S or R ) (Equation 16-2)

1.2( D + F ) + 1.6( Lr or S or R ) + 1.6 H + ( ƒ 1 L or 0.5 W ) (Equation 16-3)

1.2( D + F ) + 1.0 W + ƒ 1 L + 1.6 H + 0.5( Lr or S or R ) (Equation 16-4)

1.2( D + F ) + 1.0 E + ƒ 1 L + 1.6 H + ƒ 2 S (Equation 16-5)

0.9 D + 1.0 W + 1.6 H (Equation 16-6)

0.9( D + F ) + 1.0 E + 1.6 H (Equation 16-7)

where:

f 1 = 1 for places of public assembly live loads in excess of

100 pounds per square foot (4.79 kN/m ² ), and parking garages; and 0.5 for other live loads.

f 2 = 0.7 for roof configurations (such as saw tooth) that do

not shed snow off the structure, and 0.2 for other roof configurations.

Exceptions:

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

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STRUCTURAL DESIGN

mic design categories. 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 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.

Lateral force-resisting systems shall meet seismic detailing requirements and limitations prescribed in this code and ASCE 7 Chapters 11, 12, 13, 15, 17 and 18 as applicable, even where wind load effects are greater than seismic load effects.

Exception: References within ASCE 7 to Chapter 14 shall not apply, except as specifically required herein.

Loads and load combinations on storm shelters shall be determined in accordance with ICC 500.

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

1613.2.1 Mapped acceleration parameters. The parameters SS and S 1 shall be determined from the 0.2 and 1-second spectral response accelerations shown on Figures 1613.2.1(1) through 1613.2.1(8). Where S 1 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 Seismic Design Category A.

Exception: [OSHPD 1R, 2 & 5] Seismic Design Cate- gory shall be in accordance with exception to Section 1613.2.5.

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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.

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 other than coastal high hazard areas or coastal A zones:

1.1. The elevation of the lowest floor, including the basement, as required by the lowest floor elevation inspection in Section 110.3.3 and for the final inspection in Section 110.3.11.1.

1.2. 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 2.7.2.1 of ASCE 24, construction documents shall include a statement that the design will provide for equalization of hydrostatic flood forces in accordance with Section 2.7.2.2 of ASCE 24.

1.3. 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 coastal high hazard areas and coastal A zones:

2.1. The elevation of the bottom of the lowest horizontal structural member as required by the lowest floor elevation inspection in Section 110.3.3 and for the final inspection in Section 110.3.11.1.

2.2. 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.

2.3. For breakaway walls designed to have a resistance of more than 20 psf (0.96 kN/m ² ) determined using allowable stress design, construction documents shall include a statement that the breakaway wall is designed in accordance with ASCE 24.

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 1616.3.

1616.3.1 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 16.2.4 and 16.2.5 of ACI 318.

1616.3.2 Other bearing wall structures. Ties in bearing wall structures other than those covered in Section 1616.3.1 shall conform to this section.

1616.3.2.1 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

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STRUCTURAL DESIGN

5] Nonstructural components designated below shall have a component importance factor, Ip, equal to 1.5:

1. For components that are required for life-safety pur- poses after an earthquake, including emergency and standby power systems, mechanical smoke removal sys- tems, fire protection sprinkler systems and fire alarm control panels.

2. For medical equipment, mechanical and electrical components and components required for life support for patients.