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Santa Ana Bridge Rehabilitation and Bike Trail Structure 12/27/2004 and potential impacts to the existing drainage facilities assessed for each proposed improvement alternatives. 1.7 GEOTECHNICAL STUDY Foundation reports for Fifth Street and McFadden Avenue Bridges have been previously completed during the seismic retrofit strategy of these bridges. For the Flower Street Bridge rehabilitation, it is assumed that the proposed improvements will have insignificant load increase on existing bridge foundations (less than 3%). Thus no foundation work is anticipated, and the foundation report will not be required. During the December 14t' meeting at the City, it is determined that alternative 3 of our proposal (cantilevered slab brigge) for the proposed Flower Street Bike Path improvements over Santa Ana -Delhi Channel is the preferred option because it has minimal effect on the Delhi Channel. This alternative will require a new row of pile foundations along the channel banks. Due to the new foundations, the Flower Street Bike Path requires a Foundation Report. A preliminary foundation report will be performed in general compliance with the Caltrans Guidelines for Foundation Investigations and Reports (Version 1.2, June 2002). including an evaluation of seismicity and ARS curves, liquefaction potential, and slope stability. This report will also recommend alternative foundation types and preliminary capacities for the new foundations. TASK 1. 7.1 - SUBSURFACE INVESTIGATION It is assumed that WKA will use the existing subsurface information for a recently constructed bike lane structure downstream from the proposed bike path structure. The information will be the basis for the design of new CIDH foundations on the bike path cantilever slab. This is the direction by the City during the December 14t"'s meeting. During the course of design, if additional explorations are deemed necessary, subsurface exploration and investigation will be performed on the basis of "Extra Services". TASK 1. 7.2 - LABORATORY TESTING This item of work was deleted per the December 141" meeting for the same reasoning presented in the Subsurface Investigation task above. Similarly, during the course of design, if additional explorations are deemed necessary, Laboratory Testing will be performed on the basis of "Extra Services". TASK 1. 7.3 - ENGINEERING ANALYSES Review of the existing Bike Structure LOTB and foundation report will form the basis of our engineering analyses. We will provide preliminary engineering conclusions and recommendations regarding: • Site conditions. • Geologic and seismic hazards. • Foundation design criteria. • Stability of existing slopes. • Lateral earth pressures and resistance to lateral loads.