Caltrans awards $35M Antioch Bridge Retrofit

April 2010 – California Engineering Contractors has been awarded a $35 Million contract to retrofit the Antioch Bridge on State Route 160 by the State of California Department of Transportation. The project is scheduled to start around June 2010 and be completed towards the end of 2011.

The Antioch Bridge was designed based on criteria developed after the 1971 San Fernando Earthquake. The 9,432 foot long bridge connects Antioch in northeastern Contra Costa County with Sacramento County over the San Joaquin River. The bridge has one lane in each direction, with bicycle and pedestrian access. Average traffic on the bridge is about 15,000 vehicles per day. The bridge features two structural elements: the “Main Structure” and the “Slab Span Structure.”

The retrofit consists of jacking the bridge to replace the existing TFE/Elastometric bearings with custom designed low-profile friction pendulum isolation bearings, constructing abutment seat extensions, post-tensioning the existing bent caps, installing steel cross bracing between columns to stiffen the superstructure cross frames, installing shear keys at intermediate hinges, removing the existing curtain walls and retrofitting the existing columns by installing steel column casings and grouting the voids.