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

•► {Mr., Ms.} First Last Name Company Plan Check Number: Number, First Review Month Day, Year 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. f) 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. 13.The second floor framing specifies TJI 210 joists at the hallway adjacent to the stairway. This framing is specified as"32"on page B-14 of the structural calculations. Calculations substantiating the joist design shall be submitted for review. See IBC Section 1604.1. 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. 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 slab- on-grade while the typical foundation wall does not project above the slab per Detail 10/S3.0. 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. b) The structure is assigned to Seismic Design Category (SDC) D. The walls shall be designed as special reinforced concrete shear walls (SRCSW) with a response modification factor of R=5 per ASCE 7-10 Table 12.2-1 Item A.1. The forces from the wood-framed walls above shall be scaled per ASCE 7-10 Section 12.2.3.1 Item 1. See IBC Section 1613.1. c) The walls shall comply with the reinforcement requirements for SRCSW per ACI 318-14 Section 18.10. See IBC Section 1901.2. d) Performance of the lateral system requires rotational resistance of the concrete walls at their bases by the foundation system. Calculations shall be submitted substantiating that the foundation system provides adequate strength and stiffness to resist design loads from the structure above. See IBC Section 1604.1, 1604.4, and 1613.1, and ASCE 7-10 Section 12.7.3. e) Continuing with the previous comment, the foundation system shall comply with the seismic detailing requirements of ACI 318-14 Sections 1813.2.1. The thickened slab edge shall be designed as a grade beam per Section 18.13.3.1 as needed to provide flexural restraint for and resist uplift on the wall piers. See IBC Section 1901.2. f) The thickness of the wall is not specified on Sheet S2.1 or Detail 12/S4.2. The wall thickness should be specified for clarity. See IBC Section 1603.1. g) The holdowns are anchored in thin walls with minimal resistance to breakout. It is recommended that the top of the wall be reinforced per the requirements of ACI 318-14 Section 10.7.6.1.6. See also comments below regarding the holdown design. See IBC Section 1901.2. ZjfiD CITY OF EVERETT • 3200 Cedar Street • Everett, WA 98201 • (425) 257-8810 • Fax (425) 257-