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, <br /> Nevada: (208)342-7162 / Loc h s a <br /> Idaho: (208)342-7168 <br /> Colorado: (720)644-9246 e n gin e e r i n g <br /> Alberta: (587)774-9040 <br /> 29 May 2018 <br /> City of Everett <br /> 3200 Cedar Street <br /> Everett,Washington 98201 <br /> ATTN: James Bronder,PE <br /> Subject: Broadway Ave.&32nd Street Apartments(Plan Check Number BI710-41) <br /> Lochsa Number: 154191.00 <br /> Dear Mr.Bronder, <br /> Plan reviews are an important part of the building process and we look forward to resolving the issues brought forth <br /> by the plan reviewer. Please see summary of our responses to the structural comments indicated below: <br /> Note: All revised drawings should be marked with clouds and delta symbol S for "Addenda#5", dated 05/29/2018. <br /> Comment#1: It appears that the there is a below grade parking garage being constructed approximately <br /> 15'-0"below grade. On structural details, it appears that the shoring(soil nail wall)is being <br /> designed by another engineer. Please provide a shoring design drawings and calculations to <br /> be submitted for review. Response:APD to provide information requested. <br /> Comment#2: From the response to the comment, the Engineer of Record determined concrete podium <br /> structure to have an extreme torsion horizontal irregularity. Per ASCE 7-10 Sec 12.3.4.2, the <br /> redundancy factor of p=1.3 is required to be applied to earthquake design forces for the <br /> design of lateral force resisting elements. Please revise forces and verb with supporting <br /> design calculations that the elements can withstand the increased demands. <br /> Response:In response to your question regarding the use of p=1.0 for the concrete <br /> podium,we have revised the structural calculations and Structural Loads information <br /> on sheet S0.03 indicating p=1.3 for the concrete podium. Due to the increase of p=1.3, <br /> F10 footings were added to the four corners of the building for uplift resistance. See <br /> revised sheets S1.01A,51.01B and revised Footing Schedule on sheet S4.02.In the <br /> calculations the p factor was accounted for in the load combinations. <br /> Comment#5: It appears that the 9-factor for shear wall dowels and diaphragms were 0.75 on pages A59 <br /> and A60. Per ACI 318-14 Sec 21.2.4.1, a 9-factor of 0.6 is required unless the nominal shear <br /> capacity of the walls is greater than the shear corresponding to the development of the <br /> nominal moment capacity of the shear walls. Please indicate which 9-factor was used in the <br /> design of concrete shear walls as it is not clear in the design calculations provided.Also, <br /> please revise the 9-factors accordingly per ACI 318-14 Sec 21.2.4.2 for the diaphragm if the <br /> 9-factor for the shear design of the shear walls have been updated <br /> Response:Addendum 1 sheets A59-A64 have been revised using"-factors equal to 0.6 <br /> for the shear design of the diaphragms.See sheets B114-B117 for the revised diaphragm <br /> chord calculations and sheets B127-B130 for the revised shear wall dowel calculation <br /> We also decreased the wall dowel spacing at the 3rd floor due to increasing p=1.3.See <br /> revised details 3/S5.07,2/S7.01,3/S7.01,9/S7.02,10/S7.02,3/57.03,5/57.04 and 7/S7.04. <br /> A co-factor of 0.6,used to calculate the nominal shear capacity of the concrete shear <br /> walls,has been used in the shear wall calculations previously submitted.See added <br /> calculation sheet B134 for additional information. <br /> .2/51 <br /> Lochsa Engineering www.lochsa.com 1-866-606-9784 <br />