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

Jeff 1 leilman,Development Technician--Public Works Department RE: Owner: Wong— 19`1'Avenue SF Jun 0 2018 Page4 Documentation verifying the seismic loads in the beam design should be submitted for review. See IBC Section 1613.1 and ASCE 7-10 Section 12.4.3.2. e) Continuing with the previous comment,the overturning loads for the second floor beam "B2" are not equal and opposite for Point 4 and Point 5. The 4.5-kip value for the Point 4 load is significantly below the 6.9-kip value per page C-24.Note that the loads on this beam should include the cumulative loads from both the second and third story shear wall holdown forces. The values of the point loads should be clarified. 0 The load combinations do not appear to include the vertical seismic component per ASCE 7- 10 Sections 12.4.2.2 and 12.4.3.2. See the controlling load combinations on page B-13 as an example. The beam design should be revised. See IBC Section 1613.1. a) The software analyzes wind and seismic loads in both upward and downward directions. This is verified by the support reactions show a negative and positive result. b) The software analyzes all applicable load cases.As mentioned in comment 8,Beam BS on sheet B-14 is designed to only take overturning loads. c) See response b) above. d) The calculations have been updated to design the beams with seismic values prior to taking out dead load. See updated beam calculations B-14,B-22 and B-26 e) Point 4 only has one level of overturning force acting. Points 3 and 5 are cumulative overturning forces. I) Sheets B-15,B-23 and B-27 have been added to show the beam analysis per sections 12.4.2.2 and 12.4.3.2 of ASCE 7-10. 13. The second floor framing specifies TJI 210 joists at the hallway adjacent to the stairway. This framing is specified as "J2" on page B-14 of the structural calculations. Calculations substantiating the joist design shall be submitted for review. See IBC Section 1604.1. Calculation Sheet B-20 has been updated. Lateral System: 14. The wind loads used in the lateral analysis on pages C-18 through C-27 appear to be the allowable values from page C-7. The values do not appear to be ultimate loads as indicated in the "Shear Wall Loads and Summary" tables. The values of the loads should be verified and the calculations revised as needed. See IBC Section 1604.4. All wind values are ultimate loads. The summation of shear values on C-18 match the shear values on C-7. 15. The two-foot long first-story wood shear walls on the south building elevation are supported by concrete wall piers that are approximately 4-feet tall. The concrete walls are approximately one- half the story height with a 2: 1 aspect ratio. In addition,the walls project above the slabon-grade while the typical foundation wall does not project above the slab per Detail 10/53.0. The walls are part of the seismic force resisting system and must be designed accordingly. The following comments should be addressed: a) Calculations substantiating the design of the concrete piers shall be submitted for review. See IBC Sections 1604.1 and 1604.4.