10721 19TH AVE SE 2023-04-07 - Laserfiche WebLink

Jeff Heilman, Development'Technician--Public Works Department RE: Owner: Wong- 19`h Avenue SE June20 018 Page 6/g south wall. A detail should be provided for the corner condition substantiating the load path for the west wall to the holdown. See IBC Section 107.2.1. S2.1 has been updated with a callout to transfer shear at the corner condition. 18. The following comments should be addressed for the holdown requirements in Detail 10/S 12: a) The straps in the wall-to-wall configuration do not include the 1 1/2-inch nailing offset before the "A" dimension. The detail should be revised. See IBC Section 104.11.2,or IBC Section 2306.1 and AWC NDS-15 Table 12.5.1A. b) The lower strap in the wall-to-header configuration does not clearly specify the "A" dimension and 1 1/2-inch offset. Revise the detail as needed to clarify the installation requirements. See IBC Section 107.2.1. The holdown straps are premanufactured and test by Simpson. Our holdown detail on 10/S4.2 has end lengths that follows their requirements to achieve their tension loads. See added sheet C-30 for their detail and installation requirements. 19. Structural calculation pages C-25 through C-27 indicate that the first story shear walls on the north elevation consist of three piers at each unit. The foundation plan should provide a holdown at each end of each wall. See IBC Sections 1604.1, 1604.8.1, 1604.10, and 2306.1,and NDS-15 SDPWS Sections 3.4,4.1.4,and 4.3.6.4.2. Per detail 12/S4.1, horizontal straps are provided at openings to transfer the shear around the openings. Holdowns are only required at the end of the 3-span segment. Holdowns were added to the west end of the center and east units. 20. The structural calculations do not appear to include the design of the diaphragms. Calculations substantiating the diaphragm design shall be submitted for review. See IBC Sections 1604.1, 1613, and 2306.1. The design shall consider the following: a) Note 3 on Sheets 52.2 through 52.4 states that the sheathing is oriented perpendicular to the supporting framing. The plans include areas where the framing is oriented in two directions. The design shall consider the limiting capacity resulting from the sheathing oriented both perpendicular and parallel to the framing. See the configuration cases in AWC SDPWS-15 Table 4.2A. b) The structure has a Type 4 Horizontal Structural Irregularity and Type 4 Vertical Structural Irregularity per ASCE 7-10 Tables 12.3-1 and 12.3-2, respectively. The loads in the diaphragms shall be increased by 25%per ASCE 7-10 Section 12.3.3.4 Item 1. c) Collectors shall be provided where required. The loads in the diaphragms shall be increased by 25%per ASCE 7-10 Section 12.3.3.4 Item 1. Calculation sheets C-8 and C-18 were updated to provide diaphragm checks. 21. The shearwall holdown design has not been provided in the structural calculations. The earthquake component of the holdown forces exceeds 20%of the total uplift.The earthquake