Section 2205

The design, fabrication and erection of structural steel elements in buildings, structures and portions thereof shall be in accordance with AISC 360.

Exceptions : [OSHPD 1R, 2 & 5]

1. For members designed on the basis of tension, the slenderness ratio (L/r) shall not exceed 300, except for the design of hangers and bracing in accordance with NFPA 13 and for rod hangers in tension.

2. For members designed on the basis of compression, the slenderness ratio (KL/r) shall not exceed 200, except for the 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 2205.2.1 or 2205.2.2, as applicable.

2205.2.1 Structural steel seismic force-resisting systems. The design, detailing, fabrication and erection of structural steel seismic force-resisting systems shall be in accordance with the provisions of Section 2205.2.1.1 or 2205.2.1.2, as applicable.

2205.2.1.1 Seismic Design Category B or C. Structures assigned to Seismic Design Category B or C shall be of any construction permitted in Section 2205. Where a response modification coefficient, R, in accordance with ASCE 7, Table 12.2-1, is used for the design of structures assigned to Seismic Design Category B or C, the structures shall be designed and detailed in accordance with the requirements of AISC 341. Beam-to-column moment connections in special moment frames and intermediate moment frames shall be prequalified in accordance with AISC 341, Section K1, qualified by testing in accordance with AISC 341, Section K2, or shall be prequalified in accordance with AISC 358.

Exception: The response modification coefficient, R, designated for “Steel systems not specifically detailed for seismic resistance, excluding cantilever column systems” in ASCE 7, Table 12.2-1, shall be permitted for systems designed and detailed in accordance with AISC 360, and need not be designed and detailed in accordance with AISC 341.

2205.2.1.2 Seismic Design Category D, E or F. Structures assigned to Seismic Design Category D, E or F shall be designed and detailed in accordance with AISC 341, except as permitted in ASCE 7, Table 15.4-1. Beam-to-column moment connections in special moment frames and intermediate moment frames shall be prequalified in accordance with AISC 341, Section K1, qualified by testing in accordance with AISC 341, Section K2, or shall be prequalified in accordance with AISC 358. [OSHPD 1R, 2 & 5] All structural steel seismic force-resisting systems in ASCE 7 Table 15.4-1 shall be designed in accordance with AISC 341.

2205.2.2 Structural steel elements. The design, detailing, fabrication and erection of structural steel elements in seismic force-resisting systems other than those covered in Section 2205.2.1, including struts, collectors, chords and foundation elements, shall be in accordance with AISC 341 where either of the following applies:

1. The structure is assigned to Seismic Design Category D, E or F, except as permitted in ASCE 7, Table 15.4-1.

2. A response modification coefficient, R, greater than 3 in accordance with ASCE 7, Table 12.2-1, is used for the design of the structure assigned to Seismic Design Category B or C.

2205.3.1 Section A4. Replace Section A4.1 Item (c) as fol- lows:

(c) Locations and dimensions of protected zones. The fab- ricator shall permanently mark protected zones of struc- tural elements in the seismic force-resisting system in the building that are designated on the construction docu- ments. If these markings are obscured during construc- tion, such as after the application of fire protection, the owner’s designated representative shall re-mark the pro- tected zones as they are designated on the construction

22-4 2022 CALIFORNIA BUILDING CODE

Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. 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.

documents. Primers or paints used to mark protected zones on steel surfaces, which are to receive sprayed fire- resistance material, shall comply with California Building Code Section 704.13.3.2. 2205.3.2 Section I2. Replace Section I2.1 item (d) as follows: (d) Decking attachments that penetrate the beam flange shall not be placed on beam flanges within the protected zone, except power-actuated fasteners up to 0.18 in. diam- eter are permitted, provided that the penetration is less than 85% of beam flange thickness.

2205.4.1 Design Requirements, 2.1 Special and Interme- diate Moment Frame Connection Types, Table 2-1 Pre- qualified Moment Connections modifications. The prequalified bolted moment connections are not permitted in buildings.

Exceptions:

1. Erection bolts are permitted. 2. The approved bolted moment connection in accordance with AISC 358 Chapter 10 as permit- ted by the exception to Section 2206.2 and AISC 358-16 Supplement No. 1, Chapter 11. 3. Single-story Type V skilled nursing or intermedi- ate care facilities utilizing wood-frame or light- steel-frame construction. 2205.4.2 Moment Connection - Chapter 11. The welded sideplate steel moment connection shall be permitted pro- vided:

1. The beams shall consist of either rolled or built-up wide flange sections. 2. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 3. 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. 4. The width-to-thickness ratios for beam flanges shall not be less than 3. 5. The spacing for lateral bracing of wide flange beams, Lb, shall include the length of the side plate at beam ends. 6. The extension of the side plates beyond the face of the column shall be within the range of 0.77d to 1.0d. 7. The gap-to-side plate thickness ratio shall range from 2.1 to 2.3. 8. Demand critical fillet welds {2}, {5}, {5a} and {7} shall have Magnetic Particle Testing (MT) in accor- dance with AWS D1.1 for procedure, technique and acceptance. Inspect the beginning and end of these welds for a 6-inch length, plus any location along the length of the weld where a start and restart is visually noted for a distance of 6 inches on either side of the start/stop location. 2205.4.3 Bolted Moment Connection - Chapter 11, Sup- plement No. 1. The bolted sideplate steel moment connec-

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tion in accordance with AISC 358-16 Supplement No. 1 shall be permitted provided:

1. A linear analysis procedure shall be used for design of the SMF and IMF systems using the bolted side- plate connection when permitted in accordance with ASCE 7. Nonlinear procedures will be considered as an alternative system. 2. The beams shall consist of either rolled or built-up wide flange sections. Columns shall consist of rolled or built-up wide flange sections or noncomposite built-up box or HSS with a minimum wall thickness of ³ /4 inch (19 mm), or satisfy the requirements of width-to-thickness ratios of highly ductile members in AISC 341-16. 3. The biaxial dual-strong axis and column minor axis configurations of the moment connection shall be considered as an alternative system. 4. For SMF and IMF systems, on the sideplate stan- dard or configuration A the U-shaped cover plates shall be used with the k dimension extension. The k dimension extension length is defined as beam depth db/6, rounded to the nearest ¹ /2 inch (12.7 mm). 5. The hinge-to-hinge span to beam depth, Lh/d, shall be greater than or equal to 4.5. 6. The width-to-thickness ratios for beam flanges shall not be less than 3.5.

Exception: For width-to-thickness ratios less than 3.5 the Cpr shall be calculated in accordance with that for welded sideplate connections but in no case shall the width-to-thickness ratio be less than 3.0. 7. The minimum bolt-to-bolt spacing shall not be less than 3 bolt diameters. 8. The extension of the side plates beyond the face of the column shall be within the range of 0.65d to 1.5d. 9. The gap-to-side plate thickness ratio shall range from 2.1 to 2.3. 10. Demand Critical fillet welds {2}, {5}, {5a} and {8} shall have Magnetic Particle Testing (MT) in accor- dance with AWS D1.1 for procedure, technique and acceptance. Inspect the beginning and end of these welds for a 6-inch (152 mm) length, plus any loca- tion along the length of the weld where a start and restart is visually noted for a distance of 6 inches (152 mm) on either side of the start/stop location. 11. The connection specific factor to account for peak connection strength, Cpr, shall be between 1.15 and 1.35. Calculations shall be submitted to OSHPD for review and approval. 12. For in-plane collectors transferring axial loads into the sideplate connection, coordination between side- plate and the registered design professional in responsible charge will be required to confirm the collector connection is sufficient to transfer the load into the moment frame system. This requirement shall be satisfied by designing the sideplate connec-

Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. 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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tions in the first bay of a multi-bay sideplate moment frame or an end bay to have a minimum connection capacity, including combined shear (Vu + Vg) and moment (Mpr) demands, of at least 1.2 times the Mpr at the plastic hinge location when the axial load, as determined by ASCE 7, Section 12.10.2.1 without Ωo, exceeds 0.1 FyAg of the sideplate beam. 13. A complete frame analysis for gravity and design wind loading using LRFD load combinations in Sec- tion 1605.1 shall be performed including Demand/Capacity Ratios. Frame beam member nominal moment strengths (Mn) used for gravity and design wind loading for the bolted sideplate connec- tion using Class A or Class B faying surfaces shall be taken as 0.80FyZ for frame beams up to 300 plf and 0.60FyZ for frame beams greater than 300 plf. 14. For moment frame beams with maximum beam shear greater than 90 percent of the vertical bolt shear capacity, a secondary check is to be provided to confirm the vertical bolt shear capacities are suf- ficient. 15. Bolted sideplate connections used on heavy-shallow frame beams for beams greater than 200 plf and shallower than 24 inches (610 mm) in depth shall be considered as an alternative system. 16. Skewed beams shall utilize the link-beam fabrication method with CJP welded splices for skew angles. The skew angle shall be less than 15 degrees. 17. For two-sided bolted sideplate connections sharing the same side plates at the same height and depth across the column, the vertical offset in the beams shall not exceed 10 inches (254 mm).