Section 2205A

STRUCTURAL STEEL

2205 A .1 General. The design, fabrication and erection of structural steel elements in buildings, structures and portions thereof shall be in accordance with AISC 360.

Exceptions: [OSHPD 1 & 4]

1. 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.

2. 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 accor- dance with NFPA 13.

2205 A .2 Seismic design. Where required, the seismic design, fabrication and erection of buildings, structures and portions thereof shall be in accordance with Section 2205 A .2.1 or 2205 A .2.2, as applicable.

2205 A .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 A .2.1.1 or 2205 A .2.1.2, as applicable.

2205 A .2.1.1 Seismic Design Category B or C. Not permitted by DSA-SS and OSHPD.

2205 A .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. 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.

2205 A .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 A .2.1, including struts, collectors, chords and foundation elements, shall be in accordance with AISC 341.

2205A.3.1 Section B5. Modify Section B5.2(a) as follows: (a) The forces specified in this section need not be applied to the diagonal members of the truss diaphragms and their connections, where each diagonal bracing member resists no more than 30 percent of the diaphragm shear at each line of resistance and where these members and connections conform to the requirements of Sections F2.4a, F2.5a, F2.5b and F2.6c. Braces in K- or V- configurations and braces supporting gravity loads other than self-weight are not permitted under this exception.

22A-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.

2205A.4.4 Section E2. Replace Section E2.6c Item (a) by the following:

(a) Use of IMF connections designed in accordance

with ANSI/AISC 358 shall be as modified in Sec- tion 2205A.5.2. 2205A.4.5 Section E3. Replace Section E3.6b Item (a) by the following:

(a) 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. 2205A.4.6 Section E3. Replace Section E3.6c Item (a) by the following:

(a) Use of SMF connections designed in accordance

with ANSI /AISC 358 shall be as modified in Sec- tion 2205A.5. 2205A.4.7 Section F2. Special concentrically braced frames (SCBF) modifications

5b. Diagonal braces, Add a new section as follows. (d) The use of rectangular or square HSS are not per-

mitted for bracing members, unless filled solid with cement grout having a minimum compressive strength of 3000 psi at 28 days. The effects of com- posite action in the filled composite brace shall be considered in the sectional properties of the sys- tem where it results in the more severe loading condition or detailing. 2205A.4.8 Section F3. Modify Section F3.6e Item 2 as fol- lows:

Exception is not permitted. 2205A.4.9 Section K2. Replace Section K2.3b as follows:

The size of the beam or link used in the test specimen shall be within the following limits:

1. The test beams or links shall be no less than 100 percent of the depth of the prototype beam or link.

2. The test beams or links shall be no less than 100 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 sec- tion shall be permitted subject to peer review and approval by the enforcement agency.

2205A.4.10 Section K2. Modify Section K2.8 by the fol- lowing:

The test specimen must sustain the required inter- story drift angle, or link rotation angle, and inelastic rotation for at least two complete loading cycles.

2205A.5.1. Design Requirements, 2.1 Special and Inter- mediate Moment Frame Connection Types, Table 2-1 Pre- qualified Moment Connections modifications.

STEEL

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 2206A.2 and AISC 358-16 Supplement No. 1, Chapter 11. 2205A.5.2 Moment Connection - Chapter 11. The welded side plate 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. 2205A.5.3 Bolted Moment Connection - Chapter 11, Supplement No. 1. The bolted sideplate steel moment con- nection 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.

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.

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.

STEEL

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- 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.

by designing the sideplate connec-_ 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 1605A.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 0.80 FyZ for frame beams up to 300 plf and 0.60 FyZ 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).