Heads up: There are no amended sections in this chapter.
|Adopt entire chapter||X||X||X|
|Adopt entire chapter as amended (amended sections listed below)|
|Adopt only those sections that are listed below|
|Chapter / Section|
The provisions of this chapter govern the quality, design, fabrication and erection of steel construction.
The scope of application of Chapter 22A is as follows:
- Structures regulated by the Division of the State Architect-Structural Safety (DSA-SS), which include those applications listed in Section 188.8.131.52. These applications include public elementary and secondary schools, community colleges and state-owned or state-leased essential services buildings.
- 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: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopting agency, as follows:
- Division of the State Architect-Structural Safety:
[DSA-SS] For applications listed in Section 184.108.40.206.
- Office of Statewide Health Planning and Development:
Identification of structural steel elements shall be in accordance with AISC 360. Identification of cold-formed steel members shall be in accordance with AISI S100. Identification of cold-formed steel light-frame construction shall also comply with the requirements contained in AISI S200 or AISI S220, as applicable. Other steel furnished for structural load-carrying purposes shall be properly identified for conformity to the ordered grade in accordance with the specified ASTM standard or other specification and the provisions of this chapter. Steel that is not readily identifiable as to grade from marking and test records shall be tested to determine conformity to such standards.
Painting of structural steel elements shall be in accordance with AISC 360. Painting of open-web steel joists and joist girders shall be in accordance with SJI CJ, SJI JG, SJI K and SJI LH/DLH. Individual structural members and assembled panels of cold-formed steel construction shall be protected against corrosion in accordance with the requirements contained in AISI S100. Protection of cold-formed steel light-frame construction shall be in accordance with AISI S200 or AISI S220, as applicable.
When shear and/or tensile forces are intended to be transferred between column base plates and anchor bolts, provisions shall be made in the design to eliminate the effects of oversized holes permitted in base plates by AISC 360 by use of shear lugs and/or welded shear transfer plates or other means acceptable to the enforcement agency, when the oversized holes are larger than the anchor bolt by more than 1/8 inch (3.2 mm). When welded shear transfer plates and shear lugs or other means acceptable to the enforcement agency are not used, the anchor bolts shall be checked for the induced bending stresses in combination with the shear stresses.
The design, fabrication and erection of structural steel elements in buildings, structures and portions thereof shall be in accordance with AISC 360.
- For members designed on the basis of tension, the slenderness ratio (L/r) shall not exceed 300, except for design of hangers and bracing in accordance with NFPA 13 and for rod hangers in tension.
- For members designed on the basis of compression, the slenderness ratio (KL/r) shall not exceed 200, except for design of hangers and bracing in accordance with NFPA 13.
Where required, the seismic design, fabrication and erection of buildings, structures and portions thereof shall be in accordance with Section 2205A.2.1 or 2205A.2.2, as applicable.
Not permitted by DSA-SS and OSHPD.
Structures assigned to Seismic Design Category D, E or F shall be designed and detailed in accordance with AISC 341.
Add Section D1.6 as follows:
6. Diaphragm bracing systems. The required strength of diagonal bracing members used as the diaphragm shall be determined from either of the following:
- The load effect resulting from the diaphragm analysis per the applicable building code provided the members satisfy all of the following requirements:
- Diagonal bracing members comply with Section D1.1 for moderately ductile members.
- Each diagonal bracing member resists no more than 30 percent of the diaphragm shear at each line of resistance.
- Diagonal bracing members shall not support gravity loads other than self-weight.
- The slenderness ratio (KL/r) of diagonal bracing members shall not exceed , except tension-only bracing.
- The load effect required for collectors using the load combinations stipulated in the applicable building code.
Modify Section D2.6c(b)(ii) as follows:
(ii) the moment calculated using the load combinations of the applicable building code, including the amplified seismic load, provided the connection or other mechanism within the column base is designed to have the ductility necessary to accommodate the column base rotation resulting from the design story drift.
Add Section F1.4c as follows:
4c. Multi-tiered braced frames: Braced frames configured with two or more tiers of bracing between diaphragm levels or locations of out-of-plane support shall comply with the additional requirements of Section F2.4e.
Modify Section F2.3 Exception (2)(a) as follows:
(a) The maximum of the forces determined using load combination stipulated by the applicable building code including the amplified seismic load, applied to the building frame model in which all compression braces have been removed and those determined with no compression braces removed per D1.4a(2).
Modify Section F2.4a by adding the following:
Where each framing bay on a line of resistance does not have opposing diagonal braces within the same column bay, then the collector forces along that line shall be designed considering the redistribution of seismic forces to other bays as a result of the post-buckled redistribution of loads using the analysis requirements of Section F2.3. The collector shall not be designed for a load less than that stipulated by the applicable building code.
Add Section F2.4e as follows:
4c. Multi-tiered braced frames: Braced frames configured with two or more tiers of bracing between diaphragm levels or locations of out-of-plane support shall comply with the additional requirements of this section:
- Braces shall be used in symmetrical pairs at every tier level.
- Horizontal beams at intermediate tier levels for V- and inverted V-brace configurations shall have out-of-plane strength, stiffness, and beam-to-column connections adequate to resist torsional moments arising from brace buckling when braces are designed to buckle out-of-plane.
- Columns shall be restrained against rotation about their longitudinal axis at each intermediate tier level and shall resist out-of-plane bending moments due to second-order effects, geometric imperfections, and out-of-plane brace buckling.
[OSHPD 1 and 4]
Modify glossary by adding the following:
Inelastic Rotation: The permanent or plastic portion of the rotation angle between a beam and the column, or between a link and the column of the test specimen, measured in radians. The inelastic rotation shall be computed based upon an analysis of the test specimen deformations. Sources of inelastic rotation include yielding of members and connectors, yielding of connection elements and slip between members and connection elements. For beam-to-column moment connections in special moment frames, the inelastic rotation is represented by the plastic chord rotation angle calculated as the plastic deflection of the beam or girder, at the center of its span divided by the distance between the center of the beam span and the centerline of the panel zone of the beam-column connection. For link-to-column connections in eccentrically braced frames, inelastic rotation shall be computed based upon the assumption that inelastic action is concentrated at a single point located at the intersection of the centerline of the link with the face of the column.
Replace Section E3.6b Item 1 by the following:
- The connection shall be capable of sustaining an interstory drift angle of at least 0.04 radians and an inelastic rotation of 0.03 radians.
Special concentrically braced frames (SCBF) modifications
5b. Diagonal braces, Add a new section as follows.
(4) The use of rectangular or square HSS are not permitted for bracing members, unless filled solid with cement grout having a minimum compressive strength of 3000 psi at 28 days. The effects of composite action in the filled composite brace shall be considered in the sectional properties of the system where it results in the more severe loading condition or detailing.
Modify Section F3.6e Item 2 as follows:
Exception is not permitted.
Replace Section K2.3b as follows:
The size of the beam or link used in the test specimen shall be within the following limits:
- At least one of the test beams or links shall be no less than 100 percent of the depth of the prototype beam or link. For the remaining specimens, the depth of the test beam or link shall be no less than 90 percent of the depth of the prototype beam or link.
- At least one of the test beams or links shall be no less than 100 percent of the weight per foot of the prototype beam or link. For the remaining specimens, the weight per foot of the test beam or link shall be no less than 75 percent of the weight per foot of the prototype beam or link.
The size of the column used in the test specimen shall properly represent the inelastic action in the column, as per the requirements in Section K2.3a. In addition, the depth of the test column shall be no less than 90 percent of the depth of the prototype column.
Extrapolation beyond the limitations stated in this section shall be permitted subject to peer review and approval by the enforcement agency.
Modify Section K2.8 by the following:
The test specimen must sustain the required interstory drift angle, or link rotation angle, and inelastic rotation for at least two complete loading cycles.
[OSHPD 1 and 4]
Design Requirements, 2.1 Special and Intermediate Moment Frame Connection Types, Table 2-1 Prequalified Moment Connections modifications.
The prequalified bolted moment connections are not permitted in buildings.
The welded side plate steel moment connection shall be permitted provided:
- The beams shall consist of either rolled or built-up wide flange sections.
- The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system.
- For SMF and IMF systems, U-shaped cover plates shall be used and the hinge-to-hinge span to beam depth, Lh/d, shall be greater than or equal to 5.
- The width-to-thickness ratios for beam flanges shall not be less than 3.
- The spacing for lateral bracing of wide flange beams, Lb, shall include the length of the side plate at beam ends.
- The extension of the side plates beyond the face of the column shall be within the range of 0.77d to 1.0d.
- The gap-to-side plate thickness ratio shall range from 2.1 to 2.3.
Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1, is used for the design of systems of structural steel acting compositely with reinforced concrete, the structures shall be designed and detailed in accordance with the requirements of AISC 341 and shall be considered as an alternative system.
Exception: Steel and concrete composite special moment frame with the approved moment connections in accordance with AISC 358 Chapter 10 shall be permitted, provided:
- Beams are provided with reduced beam sections (RBS),
- Web extension to beam web two-sided fillet weld welds are sized to develop expected strength of the beam web and shall not be less than a 1/4 inch fillet weld, and
- The built-up box column wall thickness shall not be less than 1.25 inches and the HSS column wall thickness shall not be less than 1/2 inch.
Where required, the seismic design of buildings shall be in accordance with the additional provisions of Section 2205A.2 or 2211A.6.
The registered design professional shall indicate on the construction documents the steel joist and steel joist girder designations from the specifications listed in Section 2207A.1; and shall indicate the requirements for joist and joist girder design, layout, end supports, anchorage, bridging design that differs from the SJI specifications listed in Section 2207A.1, bridging termination connections and bearing connection design to resist uplift and lateral loads. These documents shall indicate special requirements as follows:
- Special loads including:
- Special considerations including:
- 2.1. Profiles for joist and joist girder configurations that differ from those defined by the SJI specifications listed in Section 2207A.1.
- 2.2. Oversized or other nonstandard web openings.
- 2.3. Extended ends.
- Live and total load deflection criteria for joists and joist girder configurations that differ from those defined by the SJI specifications listed in Section 2207A.1.
The steel joist and joist girder manufacturer shall design the steel joists and steel joist girders in accordance with the SJI specifications listed in Section 2207A.1 to support the load requirements of Section 2207A.2. The registered design professional shall be permitted to require submission of the steel joist and joist girder calculations as prepared by a registered design professional responsible for the product design. Where requested by the registered design professional, the steel joist manufacturer shall submit design calculations with a cover letter bearing the seal and signature of the joist manufacturer's registered design professional. In addition to the design calculations submitted under seal and signature, the following shall be included:
- Bridging design that differs from the SJI specifications listed in Section 2207A.1, such as cantilevered conditions and net uplift.
- Connection design for:
- 2.1. Connections that differ from the SJI specifications listed in Section 2207A.1, such as flush-framed or framed connections.
- 2.2. Field splices.
- 2.3. Joist headers.
Steel joist placement plans shall be provided to show the steel joist products as specified on the approved construction documents and are to be utilized for field installation in accordance with specific project requirements as stated in Section 2207A.2. Steel joist placement plans shall include, at a minimum, the following:
- Listing of applicable loads as stated in Section 2207A.2 and used in the design of the steel joists and joist girders as specified in the approved construction documents.
- Profiles for joist and joist girder configurations that differ from those defined by the SJI specifications listed in Section 2207A.1.
- Connection requirements for:
- 3.1. Joist supports.
- 3.2. Joist girder supports.
- 3.3. Field splices.
- 3.4. Bridging attachments.
- Live and total load deflection criteria for joists and joist girder configurations that differ from those defined by the SJI specifications listed in Section 2207A.1.
- Size, location and connections for bridging.
- Joist headers.
[DSA-SS] Joist and joist girder design calculations and profiles with member sizes and connection details, and joist placement plans shall be provided to the enforcement agency and approved prior to joist fabrication, in accordance with the California Administrative Code (Title 24, Part 1). Joist and joist girder design calculations and profiles with member sizes and connection details shall bear the signature and stamp or seal of the registered engineer or licensed architect responsible for the joist design. Alterations to the approved joist and joist girder design calculations and profiles with member sizes and connection details, or to fabricated joists are subject to the approval of the enforcement agency.
At completion of manufacture, the steel joist manufacturer shall submit a certificate of compliance to the owner or the owner's authorized agent for submittal to the building official as specified in Section 1704.5 stating that work was performed in accordance with approved construction documents and with SJI specifications listed in Section 2207A.1.
The chords of all joists shall be laterally supported at all points where the chords change direction.
The design, fabrication and erection including related connections, and protective coatings of steel cables for buildings shall be in accordance with ASCE 19.
The design of cold-formed carbon and low-alloy steel structural members shall be in accordance with AISI S100. The design of cold-formed stainless-steel structural members shall be in accordance with ASCE 8. Cold-formed steel light-frame construction shall also comply with Section 2211A. Where required, the seismic design of cold-formed steel structures shall be in accordance with the additional provisions of Section 2210A.2.
The design and construction of cold-formed steel decks shall be in accordance with this section.
Steel roof decks shall be permitted to be designed and constructed in accordance with ANSI/SDI-RD1.0. The base material thickness of steel deck shall not be less than 0.0359 inch (0.9 mm) (20 gage).
Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1, is used for the design of cold-formed steel structures, the structures shall be designed and detailed in accordance with the requirements of AISI S100 and ASCE 8.
The design and installation of structural and nonstructural members utilized in cold-formed steel light-frame construction where the specified minimum base steel thickness is not greater than 0.1180 inches (2.997 mm) shall be in accordance with AISI S200 and Sections 2211A.2 through 2211A.7, or AISI S220, as applicable.
Headers, including box and back-to-back headers, and double and single L-headers shall be designed in accordance with AISI S212 or AISI S100.
Cold-formed steel trusses shall be designed in accordance with AISI S214, Sections 2211A.3.1 through 2211A.3.4 and accepted engineering practice.
The truss design drawings shall conform to the requirements of Section B2.3 of AISI S214 and shall be provided with the shipment of trusses delivered to the job site. The truss design drawings shall include the details of permanent individual truss member restraint/bracing in accordance with Section B of AISI S214 where these methods are utilized to provide restraint/bracing.
Not permitted by DSASS and OSHPD.
The owner or the owner's authorized agent shall contract with a registered design professional for the design of the temporary installation restraint/bracing and the permanent individual truss member restraint/bracing for trusses with clear spans 60 feet (18 288 mm) or greater. Special inspection of trusses over 60 feet (18 288 mm) in length shall be in accordance with Section 1705A.2.
Framing for floor and roof systems in buildings shall be designed in accordance with either AISI S210 or AISI S100.
Light-frame shear walls, diagonal strap bracing that is part of a structural wall and diaphragms used to resist wind, seismic and other in-plane lateral loads shall be designed in accordance with AISI S213.
Shear wall assemblies in accordance with Section C2.2.3 of AISI-S213 are not permitted within the seismic force-resisting system of buildings
Not permitted by DSA-SS and OSHPD.
Light modular steel moment frame buildings shall be constructed of factory-assembled modules comprising a single-story moment-resisting space frame supporting a floor and roof. Individual modules shall not exceed a width of 14 feet (4.25 m) nor a length of 72 feet (22 m). All connections of beams to corner columns shall be designed as moment-resisting in accordance with the criteria of Section 2212A.2. Modules may be stacked to form multistory structures not exceeding 35 feet or two stories in height. When stacked modules are evaluated separately, seismic forces on each module shall be distributed in accordance with Section 12.8.3 of ASCE 7, considering the modules in the stacked condition. See Section 2212A.2.5 of this code.
The design, fabrication and erection of light modular steel moment-frame buildings shall be in accordance with the AISC Specification for Structural Steel Buildings (ANSI/AISC 360) and the AISI North American Specification for the Design of Cold Formed Structural Members (AISI/COS/NASPEC), as applicable, and the requirements of this section. The maximum dead load of the roof and elevated floor shall not exceed 25 psf and 50 psf (1197 Pa and 2394 Pa), respectively. The maximum dead load of the exterior walls shall not exceed 45 psf (2155 Pa).
In addition to the other requirements of this code, the design, materials and workmanship of light modular steel moment frames shall comply with the requirements of this section. The response modification coefficient R shall be equal to 31/2. Cd and Ω0 shall be equal to 3.0.
Beams, columns and connection materials shall be limited to those materials permitted under the AISC Specification for Structural Members (ANSI/AISC 360) and the AISI North American Specification for the Design of Cold-Formed Structural Members (AISI/COS/NASPEC).
At each moment-resisting connection the following shall apply:
|Fybi||=||The specified yield stress of beam "i."|
|Fycj||=||The specified yield stress of column "j."|
|Sbi||=||The flexural section modulus of each beam "i" that is moment connected to the column "j" at the connection.|
|Scj||=||The flexural section modulus of each column "j" that is moment connected to the beam "i" at the connection.|
Weld filler metals shall be capable of producing weld metal with a minimum Charpy V-Notch toughness of 20 ft-lb at 0°F. Where beam bottom flanges attach to columns with complete joint penetration groove welds and weld backing is used at the bottom surface of the beam flange, such backing shall be removed and the root pass back-gouged, repaired and reinforced with a minimum 3/16 inch (5 mm) fillet weld.
Connections of beams to columns shall have the design strength to resist the maximum seismic load effect, Em, calculated in accordance with Section 12.4.3 of ASCE 7.
Analysis of multistory assemblies shall be permitted to consider the stacked modules as a single assembly, with restraint conditions between the stacked units that represent the actual method of attachment. Alternatively, it shall be permitted to analyze the individual modules of stacked assemblies independently, with lateral and vertical reactions from modules above applied as concentrated loads at the top of the supporting module.
High-strength bolts, nuts and washers shall be sampled and tested by an approved independent testing laboratory for conformance with the requirements of applicable ASTM standards.
[OSHPD 1 and 4] A minimum of three samples per lot, as defined in the ASTM standards for bolts [and not nuts and washers], shall be tested for tensile properties in accordance with ASTM F606, but need not exceed three samples per 400 bolts.
End-welded studs shall be tested in accordance with the requirements of the AWS D1.1, Sections 7.7 and 7.8.