The SR-4/SR-160 Connectors project connects westbound SR-4 to northbound SR-160 without diverting traffic onto Oakley streets. The project was funded with Bay Area Toll Funds and managed by Contra Costa Trasnportation Authority. Geocon provided environmental and geotechnical engineering services on this project that constructed two connector ramps and associated roadway transitions and ancillary site improvements. Making these connections included three major concrete box-girder bridges, the longest of which was 1,500 feet in length and spans over an existing connector ramp and UPRR alignment. High axial loading and lateral and moment capacity demands required the use of single large-diameter (8- to 13-foot) CIDH shafts extending to depths of 90 to 110 feet at bent support locations.
Our environmental professionals performed a preliminary site investigation for the proposed connectors to evaluate concentrations of 17 California Assessments Manual metals. Results of this investigation was used by the construction contractor for health, safety, management, and disposal evaluation purposes.
Geocon also provided geotechnical engineering and consultation during construction including observation of large-diameter CIDH foundations and driven piles.