3315 SEAWAY BLVD 2020-06-05 - Laserfiche WebLink

A Ms. Nadia Azarova Craft Architects Plan Check Number: B1810-016, First Review November 30, 2018 15.The structural calculations state that the lateral force resisting system is a steel ordinary concentrically-braced frame. However, the drawings specify moment frame connections between the beams and columns at Grids B/4, C/1, and C/4 on Plans 1/51.1 and 2/S1.1. The connections are not provided to exclusively facilitate cantilever support of the stairway framing, and lateral bracing is not provided at locations specifying moment connections. The FEM in the structural calculations indicates two-way bracing at each level for the full height of the structure on Grids B/2-4, 2/B-C, and 4/B-C. The FEM does not include moment frame connections. Furthermore, the use of moment frames is not permitted in Seismic Design Category D per ASCE 7-10 Table 12.2-1 Item CA, and it does not qualify for use per Section 12.2.5.6.1. The structural drawings shall be revised for consistency with the structural calculations. See IBC Sections 1603.1, 1604.4, and 1613.1. 16.The columns included in the lateral frames shall satisfy the requirements of AISC 341-10 Section D1.4a in addition to other load requirements. Calculations substantiating the design of the columns shall be submitted for review. See IBC Section 2205.2.1.2. 17. Structural calculations substantiating the design of the diaphragm bracing and connections are not included in the calculations package and shall be submitted for review. The angles are connected to the connection plates though one leg. The design shall consider eccentric loading in the braces and the connections. The brace-to-connection plate design shall include shear lag. The connection plate-to-structural framing forces shall be determined using a generally-accepted method (e.g., Uniform Force Method, etc.). See IBC Sections 1604.1 and 2205.1, and AISC 360-10 Sections D3, E5, F10, and H1, and Chapter J. 18. Structural calculations substantiating the design of the tension braces and their connections are not included in the calculations package and shall be submitted for review. The design load for the brace connections shall satisfy AISC 341-10 Section 6a. The connection plate- to-structural framing forces shall be determined using a generally-accepted method (e.g., Uniform Force Method, etc.). The base plates connect to the faces of the HSS columns and shall verify the strength of the column wall per AISC 360-10 Section K1 and Table K1.2. See IBC Sections 2205.1 and 2205.2.1.2, and AISC 360-10 Chapters D and 3. 19.The design of the column bases shall satisfy the requirements of AISC 341-10 Section D2.6. Calculations substantiating the design shall be submitted for review. See IBC Sections 1604.2, 1613.1, and 2205.2.1.2. The following comments shall be addressed: a. Calculations substantiating the design of the column bases for axial and shear loading shall be designed per AISC 341-10 Sections D2.6a and D2.6b. b. The anchorage of columns to the foundations shall be performed per ACI 318-14 Chapter 17. See AISC 341-10 Section D2.6; note that this section references ACI 318 Appendix D for the design of concrete anchors, which not occurs in Chapter 17. The anchors shall satisfy the requirements of ACI 318-14 Sections 17.2.3.4.2 and 17.2.3.5.2. The load combinations of ASCE 7-10 Section 12.4.2.3 and 12.4.3.2, including the vertical seismic load effect per Section 12.4.2.2, shall apply. c. Continuing with the previous comment, the concrete footings in Detail 1/S1.2 do not have sufficient weight to resist the uplift forces from the braced frames. The connections between the footings and the slab-on-grade shall similarly satisfy the requirements of ACI 318-14 Chapter 17. O 3200 Cedar Street �:/ 425.257.8800 O everettpw@everettwa.gov Everett,WA 98201 425.257.8882 fax everettwa.gov