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PROPO3~4L TO CITY OF SANTA ANA <br />AME,57) MENT TO BRIDGE RETROFIT CONTRACT <br />SEISMIC RETROFIT STRA TEG Y <br /> <br />PAGE22 <br /> <br />SCOPE OF WORK FOR <br /> <br />FAIRVIEW STREET BRIDGE OVER SANTA ANA RIVER <br /> Seismic Retrofit <br /> <br />PROJECT UNDERSTANDING <br /> <br />City of Santa Ana intends to provide seismic retrofit to the existing seven span Fairview Street <br />Bridge over Santa Ana River (Bri. No. 55C-0513). The bridge was constructed in 1962 by <br />County of Orange Highway Department. The structure is 52'side. Constructed of concrete "T' <br />girders, supported over eight concrete piers founded on concrete mandrel piles. The structure has <br />a high skew angle of 54.4 degrees, and all the supports are parallel. A seismic retrofit design was <br />prepared by a consultant retained by Caltrans in 1991, and the retrofit mainly consist of cable <br />restrainers and pipe seat extenders across the two expansion joints, and adding concrete shear <br />keys at abutments. The retrofit was not constructed. The City is requesting additional consultant <br />service to review the original seismic retrofit, and to provide revisions and modifications to the <br />original retrofit due to the changes in seismic analysis and design codes instituted by Caltrans <br />since 1994 and was most recently updated in 2000 with the publication of the Seismic Design <br />Criteria (SDC 1.2). <br /> <br />WKA will provide the services following the standard project development for a seismic retrofit <br />project, starting with the seismic retrofit strategy analysis and report. The proposed seismic <br />retrofit will be reviewed and approved by Caltrans in a Seismic Retrofit Strategy Sessions to be <br />held at Caltrans Engineering Services Center (ESC) office in Sacramento. The approval will <br />form the basis for design for the seismic retrofit design and construction plans, specification and <br />estimates. The proposed scope is outlined below. <br /> <br />WKA's subconsultant- RBF Consulting, will be providing environmental evaluation of the <br />Fairview Bridge, as well processing environmental permits for four structures in the City of Santa <br />Ana as part of the seismic retrofit program. The fours structures are First Street over SA River, <br />Fifth Street over SA River, and McFadden Avenue Bridge over SA River. <br /> <br />STRUCTURE DESIGN- Seismic Retrofit Design <br /> <br />1- SEISMIC RETROFIT STRATEGY DEVELOPMENT/ BRIDGE GENERAL <br />PLANS <br /> <br />WKA will prepare the Seismic Retrofit Strategy to reflect all the geometric, foundation <br />structural details and design standard of the existing structure. The general plan (Seismic <br />Retrofit) will follow Caltrans OSFP I&P Guide Section 4-2 "Structure Type Selection". <br />In. We will investigate the seismic safety and structural integrity of the existing structure follows <br />the latest SDC, as well as applicable MTD sections pertinent to seismic retrofit ( such as MTD <br />20-4). <br /> <br />Page 3 of 22 <br /> <br /> <br />