3000 ROCKEFELLER AVE ADMIN BLDG WEST 2022-05-13

Mr. Mark Thunberg Snohomish County Property Management Plan Check Number: 131802-011, First Review (Structural) June 18, 2018 exclusively supports assembly areas. The load is not reducible per IBC Table 1607.1 Footnote "m". The design should be revised. c. The elevator lobby areas are designed for 80 psf loading. The framing in these areas only supports assembly loading and should be designed for 100 psf per Sheets S-102 and S-103. The design should be revised. d. The office areas appear to be designed for an 80 psf unreducible load, which exceeds the 50 psf reducible load and 15 psf unreducible partition load per Sheet S-103. Please confirm. If the loading is revised in response to the comments above, the loads should be separated so that the 15 psf load is not reduced. e. A load map for the roof framing is not included and should be submitted for review. The map should include the penthouse areas if not explicitly modeled. f. The Roof Load Map 16/S-103 specifies a cladding weight of 15 psf. The calculations indicate line loads of 200 psf. Based on the 14 to 15 foot stories heights per the architectural elevations, the line load will exceed 200 psf and should be increased. g. The east sides of the stairway areas are only designed for Line Load "L1". It appears that the framing on this side will also support one-half of the stairway load and should concurrently include Line Load "14". The design should be reviewed and revised. 17. The "Loading Criteria" portion of Section 1.0 in the structural calculations specifies a 100 psf "roof/snow" load. Sheet S-103 specifies a 25 psf load. The correct load should be verified. See IBC Section 1603.1 and 1604.1. 18. The load schedule in Detail 20/S-103 specifies a flat roof snow load of 25 psf. The canopy and roof on Sheets AF-102 and AF-106, respectively, have slopes of less than 1/2:12. The WABO- SEAW White Paper "Snow Load Regulations and Engineering Practices" (August, 2000) recommends applying an additional 5 psf rain surcharge for roof slopes less than 1/2:12 in addition to the 25 psf snow load. The engineer -of -record should determine if this additional load should be included in the design. The design of structural framing subjected to increased loading should be reviewed and revised as needed. See IBC Sections 1603.1.3. 19. The load combinations used in the design are specified in Section 1.3.1 of the structural calculations. IBC Equation 16-2 (i.e., 1.2D + 1.6L) should be revised to include the roof live load. The design should also include load combinations 16-3 and 16-5. The factor fl=1.0 for assembly areas (Note: Section 1605.2 appears to have a typo; reference IBC 2006 and 2009, and ASCE 7-10 Section 2.3.2 for intended application of this factor) and other live loads exceeding 100 psf. The earthquake load shall be the vertical earthquake load effect per IBC Section 1613.1 and ASCE 7-10 Section 12.4.2.2. 20. Two existing columns on Grid F'/13.1-16.1 will be demolished at all levels per Sheets S-202 through S-206. The existing floor framing will be resupported by the addition framing using backspan framing per Detail 8/S-602. Calculations substantiating the backspan design shall be submitted for review, including the beams and their connections that directly resist the backspan load. The design shall include all applicable load combinations from IBC Section 1605.2. See IBC Section 1604.1 and 1604.4. 9 age5of11 CITY OF EVERETT . 3200 Cedar Street • Everett, WA 98201 . (425) 257-8810 • Fax (425) 257-8857