3000 ROCKEFELLER AVE ADMIN BLDG WEST 2022-05-13

Mr. Mark Thunberg Snohomish County Property Management Plan Check Number: B1802-011, First Review (Structural) June 18, 2018 Foundation System: 12. The design for the shear wall foundations is provided in Section 4.2 of the structural calculations. The calculations appear substantially incomplete. Additional documentation substantiating the design should be submitted for review. The additional documentation should include but is not limited to: input modeling criteria including material strengths and cracked section properties; complete loading criteria for all footings; documentation of load combinations including vertical seismic effects per ASCE 7-10 Section 12.4.2.2; calculations for the shear and flexural design of the footings. See IBC Sections 1604.1, 1604.4, and 1613.1. 13. The "Location B" footing appears to respresent the foundation at Grid 1.5-K/12.1-13.1. The size of the footing in the calculations appears inconsistent the drawings. At a minimum, the south side of the footing appears to extend significantly farther than shown in the drawings. The design of the footing should be reviewed and revised as needed. See IBC Section 1604.4. 14. The shear wall foundation at Grid C/8-11 includes micropiles at each end. The embedment of the piles into the foundation is shown in Sections 10/S-502 and 15/S-502. The following comments should be addressed: a. Sheet S-200 specifies that the piles shall be cored through the existing footings. This should be shown in one of the sections. See IBC Sections 107.2.1. b. Calculations substantiating the capacity of the piles should be submitted for review. See IBC Section 1604.1. c. The sections show the piles embedding for most of the foundation depth. The piles do not appear to include supplemental reinforcement connecting them to the foundation. Calculations substantiating the load transfer to the piles for compression and uplift should be submitted for review. See IBC Sections 1604.1 and 1604.4. 15. Additional documentation for the design of the shear wall foundation at Grid C/8-11 should be submitted for review. See IBC Section 1604.4. The following comments should be addressed: a. The foundation appears to be designed as a monolithic element. However, the foundation encases three existing gravity footings. The foundation should be evaluated considering its actual geometry, including discontinuities in its structure. b. The foundation is anticipated to have rigid bearing zones at the ends due to the micropiles. The foundation shall be designed as needed by analysis to span between the ends and distribute vertical loads to the piles. c. The load path between the shear wall and the continuous sides of the foundation shall be substantiated. Gravity System: 16. Section 1.2.3 provides gravity loading criteria for the gravity system analysis. See IBC Sections 1604.4, 1606, and 1607. The following comments should be addressed: a. Level 02 includes an opening and framing for a stairway at Grid 3-K/12.1-13.1 that is not included in the model. The framing plan should be revised and the design verified. b. The second and fourth floors indicate a live load of 80 psf. The areas carry significant areas of 100 psf live load for assembly loading per Sheets 5-102 and S-103. The analysis appears based on use of an average value, which is not appropriate as some framing age 4 of 11 CITY OF EVERETT • 3200 Cedar Street • Everett, WA 98201 • (425) 257-8810 • Fax (425) 257-8857