The San Mateo-Hayward Bridge carries six lanes of traffic on State Route 92 between Foster City and the city of Hayward, and spans across the southern portion of the San Francisco Bay.  The total length of the bridge is about 7.1 miles, which includes a 220-foot long west approach, a 1.85-mile long main span structure and a 5.15 mile long concrete trestle on the east end.  The main span structure includes 18 single span anchor units alternating with 19 suspended spans.  The superstructure of the main span structure consists of twin steel box girders with lightweight concrete or orthotropic steel decks.  The substructure consists of steel or concrete towers supported by concrete portal frames that are founded on pile-supported foundations.  The bridge was opened to traffic in 1967.

As a part of a design team led by Carter and Burgess, Inc., Modjeski and Masters, Inc. offered engineering services for the Main Span Structure as follows: 

        Phase I - Seismic Retrofit Strategy

Reviewed “as-built” analysis

Participated in developing seismic performance criteria

Developed conceptual seismic retrofit schemes

Developed seismic retrofit strategy for the steel towers and the superstructure 

           Phase II - Preliminary Design

Prepared seismic design criteria recommendations

Developed seismic retrofit alternative for the steel towers and the deck hinges

Performed preliminary design and develop retrofit details for the selected retrofit scheme 

        Phase III - Final Design

Performed final design and develop plans for the retrofit of the steel towers and deck hinges