ESE is the structural engineer of record for design of Ten Station Platforms, Four Different Retaining Wall Segments, & Islais Creek Bridge Retrofit. Islais Creek Bridge is an existing double bascule draw bridge over Islais Creek in San Francisco built in 1950. Two of the six automobile traffic lanes of this bridge will be transformed to railroad lanes. To accommodate the new use and strengthen existing seismic deficiencies, ESE analyzed and designed the bridge for new light rail loads and strengthened the bridge for seismic loads and deformation limits per current seismic criteria of Caltrans and BCDC. Design was based on a three dimensional model, including pile foundation, subjected to site-specific response spectra, gravity, buoyancy, and earth pressure loads. Retrofit consisted of providing new CISS piles and new blockings and stoppers to prevent transverse movement of the concrete counterweight.
Bayshore Boulevard Overcrossing is an existing four span highway skew structure with concrete bents and steel plate girders. The structure has been previously retrofitted with seismic isolators. The bridge is being widened to accommodate two new railroad tracks. ESE made an independent design check of the widening design by WPK Third Street Consultants including new and existing foundations, bents, deck, superstructure plate girders, attached signs, and seismic isolators. The independent design check was based on a three dimensional model of the structure explicitly incorporating the seismic isolators, subjected to site-specific response spectra and gravity loads. The design criteria were based on Caltrans specifications and AASHTO requirements for seismic isolators.