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7.1.E. - Page 41 <br /> be selected to try to avoid underground utilities; and be sloped to avoid the need <br /> for temporary shoring. <br /> • Consultant will inspect the top one foot (or so) of uncovered piles at the edges; <br /> and examine the surface soil samples / ground water conditions. If feasible and <br /> located close enough to the edges without requiring excessive excavation, the <br /> first interior piles may also be exposed. <br /> • The excavations will then be replaced. Using Redwood City standards, <br /> Consultant can provide a recommended approach for excavation and suitable <br /> soil replacement / compaction and repair of the surface. The likely replacement <br /> material will be a controlled low strength material (controlled density fill). <br /> • Consultant will review the borings made during original construction to establish <br /> soil layering and bounds for soil properties. This will be supplemented by a <br /> geophysical test (non-destructive) at each site to establish slow-strain shear <br /> wave speeds for the site. <br /> • Consultant will perform tank — pile soil-structure interaction analyses to establish <br /> the dynamic response of the tanks under three seismic ground motions (Loma <br /> Prieta, 475-year and 2/3 x 2,475 year) for the two tank sites. <br /> • Consultant will evaluate the likely ductility demands in the pile / pile-cap <br /> connections under the Loma Prieta and the design basis ground motions. <br /> • Consultant will develop recommendations as to the seismic performance of each <br /> tank under design-basis earthquakes, and any upgrades / operational changes <br /> that are suitable. The upgrades might include: do nothing; structural <br /> improvement (new caissons) to strengthen the overall tank-pile system; lower <br /> water operating levels to reduce seismic forces; soil remediation. <br /> • Consultant will write a report that includes all findings and recommendations. <br /> Consultant will submit the report as draft, meet with Redwood City ad obtain <br /> comments, and issue as final. <br /> Should the recommendations include seismic upgrades, Consultant can then provide <br /> Redwood City with the design services to implement these upgrades. The cost of these <br /> services is not included in the base scope of this proposal. Depending on the findings, <br /> the upgrades could range from operational only (install suitable instrumentation and <br /> controls to limit operational water heights); or structural (new caissons); requiring from <br /> between 2 to 10 sheets per tank. <br /> Task 5 Bid Period Services (Optional) <br /> Consultant shall assist Redwood City staff with the application processes to obtain <br /> permits as needed. <br /> For each package to be separately bid (assumed 3) Consultant shall attend a pre-bid <br /> conference for potential bidders and respond to questions and requests for information <br /> from Contractors during the bid period. Consultant shall notify Redwood City of any <br /> potentially significant questions and requests for information. <br /> ATTY/AGR12012.001/G&E ENGINEERING Page 24 of 30 <br /> PPNr•ni r1n197 <br />