3000 ROCKEFELLER AVE ADMIN BLDG WEST 2022-05-13

Mr. Mark Thunberg Snohomish County Property Management Plan Check Number: B1802-011, First Review (Structural) June 18, 2018 27. The building has reentrant corners at all levels (i.e., Sheets S-202 through S-206) resulting in a Type 2 horizontal structural irregularity per ASCE 7-10 Table 12.3-1. The design forces for the diaphragm connections to the shear walls and collectors, and the collectors and their connections to the shear walls, shall be increased 25%. Calculations verifying the design considering the increased loading shall be submitted for review. See IBC Section 1613.1 and ASCE 7-10 Section 12.3.3.4. 28. The building has a reentrant corner at Grid F'/12.1 at all levels (i.e., Sheets S-202 through S- 206). The chord for the addition's diaphragms along Grid 12.1 should be developed into the existing structure. Calculations substantiating the chord development should be submitted for review. See IBC Section 1613.1 and ASCE 7-10 Section 12.10.1. 29. The concrete shear wall on Grid C/8-10.5 is discontinuous at the existing concrete -topped steel decks per Details 9, 10, 14, 15, 19, and 20 on Sheet S-601. The wall changes thickness from 16 to 10 inches over its height. Elevation 6/S-301 indicates coupling beams are bisected by the existing decks. The following comments should be addressed: a. The shear strength of the shear wall at the decks should be substantiated per the shear - friction criteria of ACI 318-14 Section 22.9.3 with µ=0.7k per Table 22.9.4.2. See IBC Section 1901.2. b. Detail 11/S-311 does not appear to represent the conditions for the coupling beams. A detail representing the conditions should be included, indicating the installation of the shear reinforcement and accounting for the changes in the wall thickness. 30. The structural calculations do not appear to include a design for the addition diaphragms. Calculations substantiating the design, including load transfer to the shear walls, shall be submitted for review. The connection loads to the shear walls and collectors shall be increased per ASCE 7-10 Section 12.3.3.4. See IBC Section 1604.1 and 1613.1. 31. Calculations shall be submitted for review substantiating the design of the collectors for the addition. Collectors appear to be provided on Sheets S-202 through S-206 on Grid 12.1. Verify if collectors are required at other locations, including but not limited to Grids F, G, K, and 16.1. Calculations shall include the connections between the collectors and the diaphragms and shear walls. The collectors and connections shall include the load increases per ASCE 7-10 Sections 12.3.3.4 and 12.10.2.1. See IBC Sections 1604.1 and 1613.1. 32. Calculations shall be submitted for review substantiating the design of the collectors between the existing structure and the new shear walls. Collectors are provided on Sheets S-201 through S-206 on Grids C/5-15, F/5-21, 16.1/E-F, and 19.1/E-F. Calculations shall include the connections between the collectors and the diaphragms and shear walls. Note that Details 12/5-601 and 9/S-602 appear designed to transfer tension only; the calculations shall clarify the transfer of compression loads. The collectors and connections shall include the load increases per ASCE 7-10 Sections 12.3.3.4 and 12.10.2.1. See IBC Section 1604.1 and 1613.1. Page 8 of CITY OF EVERETT • 3200 Cedar Street • Everett, WA 98201 . (425) 257-8810 • Fax (425) 257-8857