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Mr. Charlie Morgan, Jr. <br /> Charles Morgan &Associates <br /> Plan Check Number: B1805-043, Second Review <br /> fa <br /> October 24, 2018 <br /> 5. This comment has not been completely addressed. The original comment requested <br /> documentation substantiating that the concrete gravity columns comply with the detailing <br /> requirements of ACI 318-14 Section 18.4.3. The response states that the columns have <br /> been designed per Section 18.14.3.2. See IBC Section 1901.2. The following comments <br /> shall be addressed: <br /> a. The lateral analysis must be revised. See comments above. The columns shall be re- <br /> evaluated using displacements from the revised lateral analysis. <br /> b. The design displacements have been calculated using allowable-stress level forces (i.e., <br /> 0.7E). The displacements shall be calculated using strength level forces. See ASCE 7- <br /> 10 Section 12.8.6. <br /> c. The displacements do not appear to include the amplification factor Cd. The <br /> displacement calculations shall be revised. See ASCE 7-10 Equation 12.8-15. <br /> d. The displacements consider deflections due to seismic loading only. The north-south <br /> direction of the concrete structure is subjected to additional loads from active and <br /> seismic surcharge soil loads. Additional deflections due to this loading shall be included. <br /> The Cd-factor shall be included on the seismic surcharge component of the soil loading. <br /> e. The displacements consider deflections due to seismic loading in the north-south <br /> direction only. The building appears to have a torsional irregularity in the east-west <br /> direction and may result in larger deflections in this direction, particularly on the north <br /> side of the building. The maximum deflections in both direction shall be calculated. <br /> f. The calculations for the design moments and shears are not clear. Documentation <br /> substantiating the design forces shall be submitted for review. The documentation shall <br /> clarify the fixity assumptions used for each end and provide additional documentation <br /> substantiating these assumptions. Note that the fixity at each end (i.e., spread footing <br /> and elevated slab) is between free and fixed. See IBC Section 1604.4. <br /> g. Continuing with the previous comment, the rectangular columns are oriented to align <br /> their long and short dimensions parallel with both principal directions of the building. <br /> The effects of the column orientation on the induced moments and shears shall be <br /> considered to determine the maximum loading about each axis of the columns. <br /> 6. No additional comment. <br /> Additional Comments: <br /> 7. The lateral analysis of the wood structure, and subsequent distribution of forces to the <br /> diaphragms and shear walls, is based a flexible-diaphragm assumption. The wood structure <br /> has open fronts in both directions per AWC SDPWS-15 Section 4.2.5.2. A lateral analysis of <br /> the wood structure shall be performed considering rigid or semi-rigid diaphragms. See IBC <br /> Sections 1609.1, 1613.1, and 2306.1. The following comments shall be addressed: <br /> a. Distribution of lateral loads shall be determined considering the diaphragms as rigid or <br /> semi-rigid in both directions. Shear wall designs shall consider wind loading where they <br /> exceed the seismic shear loads. The entire structure must be considered in the analysis, <br /> including isolated portions that may otherwise be idealized as flexible. <br /> b. The use of a rigid diaphragms shall be substantiated per AWC SDPWS-15 Section 4.2.5. <br /> Alternatively, semi-rigid diaphragms may be used without analysis. Documentation <br /> substantiating the diaphragm stiffnesses shall be included in the calculation package. <br /> 0 3200 Cedar Street © 425.257.8800 @ everettpw@everettwa.gov <br /> Everett,WA 98201 425.257.8882 fax everettwa.gov <br />