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NABIH YOUSSEF <br />A S S O C I A T E S <br />STRUCTURAL ENGINEERS <br />December 15, 2010 <br />Fred Heidari <br />Deputy Building Official <br />City of Santa Ana <br />Planning and Building Agency <br />20 Civic Center Drive, M -19 <br />Santa Ana, CA. 92702 <br />RE: One Broadway Plaza — City of Santa Ana Plan Check, (NYA # 07332.01) <br />Structural Engineering Consulting Services <br />Dear Mr. Heidarl, <br />NYA is pleased to provide this proposal to assist the City of Santa Ana Building- and Safety Division with a <br />structural plan check of the proposed project at 1001 -1005 North Broadway Street at "One Broadway <br />Plaza ". <br />The proposed project consists of: <br />One 37 story Office Tower with basement level — approx 692,150 SF. <br />In the absence of additional information, our proposal is based on the following assumptions: <br />1. A complete 100% Construction Document package (not phased permitting) will be presented for <br />our review. We are assuming that cladding, equipment anchorage, stairs, elevators, etc. will be <br />deferred approval items not part of this review. <br />2. The building configurations, structural systems & framing for the subject building will be identical to <br />the 2008 drawings that NYA reviewed & approved previously. <br />3. All building elements shall be redesigned as required to meet the CBC 2007 code requirements. <br />Among others, we list below a few of the important code changes that may Impact the subject <br />building redesign: <br />a. It should be verified by the design team & the architectural plan reviewer if the code change <br />triggers any occupancy category changes especially with respect to the use of the two <br />story atrium spaces at building entry or any other public assembly type uses (the Building <br />Importance factor, 1, could go up). <br />b. The entire lateral force resisting system will need to redesigned & rechecked due to the <br />code change. In particular, for the 37 -story tower which utilizes a dual structural system - <br />the R factors have been reduced in the new code. New/ different redundancy checks, <br />irregularity checks, modeling requirements, P -Delta checks, etc. will need to be performed <br />as part of the new lateral design. <br />c. Design needs to be updated for new code load combinations; Design of discontinuous/ <br />irregular elements for overstrength needs to Include resistance factors. <br />d. All concrete anchorage related items need to satisfy ACI 318 -05 Appendix D requirements. <br />e. All wind design related items will need to be redone per the new code requirements. Wind <br />load requirements are more involved & higher per the new code - especially for roof <br />elements & misc. parapets, canopies etc. <br />f. Steel SMRF elements & corresponding column bases/ anchorages need to be designed <br />per AISC 2005 Seismic Provisions. <br />g. Foundations need to be redesigned corresponding to new code forces & requirements <br />incorporating new findings on reduced punching shear capacity of unreinforced concrete <br />deep sections, etc. <br />Fees: <br />50 California Street, Suite 3150, San Francisco. CA • Phone (415)397 -5213 -Fox (415)392 -9605 • www,NYASE.COM <br />LOS ANGELES IRVINE SAN FRANCISCO <br />