Union Road Bridge Replacement, Hollister, San Benito County, CA 

PARIKH provided geotechnical services for the Union Road Bridge replacement across San Benito River. The bridge replacement is a 7-span, cast-in-place, concrete box girder structure, with six -foot diameter cast-in-steel shell (CISS) piles. The project includes relocation of an intersection, realignment of roadway, and MSE wall embankments. The bridge alignment crosses the inferred fault trace of Calaveras Fault. The study compiled the locations of fault (and non-fault) observations in reports filed with the State Geologist and San Benito County Planning Department, noting the locations and rates of fault creep from published references/maps; and an estimated probable moment and magnitude of future earthquake; and potential displacements (both creep and co-seismic rupture) for structural design. Scour is also an ongoing issue at the project location. 

PARIKH conducted the Phase 1 Initial Site Assessment, field explorations, laboratory testing, engineering analyses. PARIKH developed design recommendations for the large-diameter CISS piles, retaining wall, subgrade improvements, scour considerations, fault rupture considerations, and pavement sections. PARIKH additionally provided construction support services for anticipated difficult pile driving conditions.