8417 EVERGREEN WAY 2022-05-23 - Laserfiche WebLink

• Mr. McIlvain CRM Architects&Planners, Inc. Plan Check Number: B1805-010, First Review August 1, 2018 included. Based on Section 27.2, the nominal wind base shears are approximately 50 kips and 80 kips, which exceed the values of 34.7 kips and 58.1 kips in the calculations. See IBC Section 1604.4 and 1609.1. The following comments should be addressed: See structural response letter a. The procedure used to determine the wind loading should be clarified. The notes on Sheet SO.0 should be revised as needed. b. Calculations substantiating the base shear in each direction using the wind pressures of the selected procedure shall be submitted for review. If the procedure in IBC Section 1609.6 is used, calculations for the wind pressures shall be included. c. Wind pressures on the parapets for the selected procedure shall be calculated at the parapet height and for both the windward and leeward side. See ASCE 7-10 Section 27.4.5 as an example. 23.The distribution of the wind forces to the shear wall lines appears to be based on tributary widths only and does not include torsion. The lateral wind loads shall include torsional effects as required by the selected procedure. Forces shall be increased in each line as required. See IBC Sections 1609.1 and 1609.6.4.1, and ASCE 7-10 Figure 27.4-8 and 28.4-1. See structural response letter 24. Sheet S2.0 specifies shear wall Mark 3 for the walls on Grids 1 and 4, identified in the structural calculations as SW1, SW2, and SW3. The calculations indicate a maximum 3-inch edge nail spacing. Mark 3 specifies a 4-inch spacing. The shear wall specifications on Sheet S2.0 should be revised. See IBC Section 1603.1. See structural response letter 25.The design shear wall load in the"Shear Resisting System Geometry"schedule for Wall SW3 is 15.1 kips. The input load in the spreadsheet for this wall is 13.9. The wall design should be revised. See IBC Section 1604.2. See structural response letter 26.The calculation of the holdown forces is included in the shear wall design spreadsheet. The following comments should be addressed: See structural response letter a. The holdown force includes the entire dead load in resistance. The force shall consider . 0.6D per IBC Equation 16-15. b. The holdown force based on seismic loading shall be calculated per IBC Equation 16-16. The dead load component shall be further reduced considering vertical effects per ASCE 7- 10 Sections 12.4.2.2 and 12.4.2.3 Equation 8. The earthquake component shall be increased per ACI 318-14 Section 17.2.3.4.3; see the following comment for additional information. See IBC Section 1604.10. 27.The shear wall holdown design should be performed for the earthquake loading. The earthquake component of the holdown forces exceeds 20% of the total uplift. The earthquake component shall be increased per the provisions of ACI 318-14 Section 17.2.3.4.3. In addition, the anchorage utilizies post-installed anchors and shall satisfy the provisions of Section 17.2.3.3. Revised calculations substantiating the holdown design should be submitted for review. See IBC Sections 1604.10 and 1901.2. See structural response letter 28.The shear wall holdown anchors are specified on Sheet S1.0. See IBC Section 107.2.1. The following comments should be addressed: See structural response letter Page9o,1-1"/TN) � CITY OF EVERETT • 3200 Cedar Street • Everett, WA 98201 • (425) 257-8810 • Fax (425) 25 857 —