2106 EVERETT AVE 2019-01-28 - Laserfiche WebLink

Mr. John Day Slichter Ugrin Architecture Plan Check Number: B1709-015, First Review April 27, 2018 submitted for review, including but not limited to: end shear, end flexure, crushing at the end thru-bolt, bolt shear, and bearing on the support. Note that a single bolt provides the primary shear transfer at the ends, and the bolt placement is staggered along the length and vertically. The capacity and detailing check for the bolt capacities and detailing shall consider the most severe position of the bolt in the beam depth. See IBC Sections 1604.2 and 1604.4. Please see updated drawings. Details 2 & 3/S2.2 have been added to clarify bearing conditions and column connections. The channels are intended to bear directly on the supports. The thru bolts in detail 9/S2.1 are not intended to transmit load to the wood members. Calculations substantiating the design have been provided. Lateral System: 10. Page 2 of the structural calculations provides the design wind pressures for the parapet design. The wind pressures should be revised based on the following comments. The structural design may need to be revised. See IBC Section 1609.1. a. The exposure adjustment factor (EAF) appears to be based on a height of 15 feet per ASCE 7-10 Table 30.7-2. The factor should be EAF=0.692 for a maximum parapet height of approximately 20 feet per the elevations on Sheet A4.1. Updated EAF Value. b. The windward and leeward pressures appear based on a maximum height of 15 feet. Design pressures, including the roof pressure considered for the windward pressure, shall be based on the maximum parapet height of 20 feet. See ASCE 7-10 Section 30.7.1.2 and Figure 307-1. Pressures have been updated. c. The windward and leeward parapet pressures shall consider positive and negative pressures on each side of the respective parapets per Figure 30.7-1. Based on Table 30.7- 2, the windward and leeward pressures appear to be at least 105.9 psf and 72.6 psf, respectively. Correct, pressures have been updated, these values multiplied by EAF*RF*Kzt equate to 73.3psf and 50.2psf, respectively. d. The calculations for the design of the framing and connections should be revised using the required wind pressures. The windward and leeward pressures should should be applied in the applicable directions for all portions of the structure to develop the maximum load effects. Parapet frame analysis has been re-evaluated with the higher loads. See updated calculations. 11. The design of the parapet brace framing is shown in Section 1/S2.1 and Details 4/S2.1 and 5/S2.1. The following comments should be addressed: a. The minimum required weld lengths should be specified in Detail 5/S2.1. Note that the framing in Section 1/S2.1 appears to overlap. In addition, the fit-up of the framing is not flat and will result in skews between members and gaps between welded surfaces. The weld size should be oversized to account for gaps and transfer of loads through overlapping members. See IBC Sections 1604.2 and 2205.1, AISC 360-10 Section J2, and AISC 303-10 Section 3.1.2. Please see updated detail. The web members are not intended to overlap. They attach directly to vertical chord elements. The vertical chord elements start out in-plane at the base and offset at the top connection by the thickness of the angle (1/4"). Calculations show that using 1/2"offset creates such a small angle that the gap in the framing connection at the weld does not exceed the 1/16"allowance per the AWS. Additionally the maximum member end reaction is 4.1k (LRFD) requiring 1-1/2"of 1/8" Page 4 of 6 CITY OF EVERETT • 3200 Cedar Street • Everett, WA 98201 • (425) 257-8810 • Fax (425) 257-8857