Owner: State of California
Contract value: $46,570,000
The seismic retrofit involves the main channel crossing section of the Dumbarton Bridge. Work includes structural concrete overlay at 14 existing pier footings, structural concete improvements to 16 existing pier caps, 16 structural steel jacking frames within the existing steel box girders, six friction pendulum bearings installed at each pier, replacement of two existing seismic joints, and the retrofit of two existing hinge joints. Improvements were added at both approach trestle structures by installating 28 steel pipe piles, each approximately 75 ft long and 4 ft in diameter. The piles were connected to the existing structure with structural concrete trestles.
Additional work included drainage improvements by installing a new pumping plant, 2,000 ft of 36-in drainage pipe and 2,000 ft of sheet pile cut-off wall.
Other work included removal of existing cathodic protection systems, improvements to the existing seismic monitoring electrical systems, miscellaneous electrical and fiber optic cable work, and removal of 2,200 lineal ft of the original Dumbarton Bridge (Ravenswood Pier).