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Project: Richmond San Rafael Bridge Seismic Retrofit

Client: Caltrans District 4

Caltrans is in the midst of implementing a seismic retrofit of the Richmond-San Rafael Bridge as part of the legislatively mandated Toll Bridge Seismic Retrofit Program. The main objective of the project is to increase the bridge’s strength and flexibility.

The Richmond-San Rafael Bridge was first opened to public traffic in 1956. The bridge is approximately four and a half miles of stacked traffic lane construction, with the upper deck of traffic flowing westerly and the lower deck flowing in the opposite direction. The bridge spans across the waters of San Pablo Bay and connects Marin and Contra Costa counties.

The entire portion of the bridge that spans the bay waters is supported by more than fifty pairs of concrete piers that extend well into the bay floor. The height of the bridge is also constructed to accommodate the passage of large cargo ships that provide world trade imports and exports. Each pair of existing bridge support piers were strengthened with massive concrete retrofit jackets that were fitted together by installing long bolts that extend through both jackets. This work took place both above and below the water’s surface.

Brelje & Race provided surveying services associated with the seismic retrofit of the Bridge, including construction layout for bolt patterns on every retrofit jacket (as many as 30 holes each on more than 50 jackets), which was essential to strengthen the bridge support system; as well as performing a control survey that allows Caltrans to monitor any future bridge movement that could result from an earthquake, greatly enhancing bridge safety in the long run.