Caltrans Toll Bridge Model Maintenance & Strong Motion Implementation Program

During the California Toll Bridge Seismic Retrofit Program for Caltrans, SC Solutions was asked to conduct seismic evaluations of several of the toll bridges and their approach structures. These bridges include the San Francisco-Oakland Bay Bridge (both the steel truss East Spans and steel suspension West Spans bridges), the 1927 and 1958  Carquinez Strait Bridges, the San Diego-Coronado  Bridge, and the 1962 Benicia-Martinez Bridge.

Seismic performance of each of these bridges was evaluated using state of the art nonlinear time history seismic analysis and performance based design methodologies. Seismic retrofit strategies were developed and optimized into final designs that were successfully constructed.

Upon completion of the design phase of the program, SC Solutions was awarded a contract to maintain and improve the analytical models of nine major California toll bridges under the program.  The types of bridges range from steel suspension to steel truss to concrete box girder, and many more.  The nine toll bridges in the program include:

• San Francisco - Oakland Bay Bridge
• San Diego - Coronado Bridge
• Benicia - Martinez Bridges (1962 bridge and 2007 bridge)
• Carquinez Strait Bridges (1958 bridge and 2003 bridge)
• San Mateo - Hayward Bridge
• Richmond - San Rafael Bridge
• Vincent Thomas Bridge

SC Solutions developed a format neutral database to maintain these bridge seismic retrofit models.  The capability to output the FE models to newer versions of ADINA and to other software has allowed Caltrans to continue to use these analysis models in earthquake planning, component upgrades/retrofits, and longterm asset management.

The maintenance of the bridge models included model upgrade and refinement, calibration of the models to field measurements and implementation of a Strong Motion Instrumentation Program (SMIP).  Additionally, SC was tasked with creating and implementing a post-earthquake emergency response plan to determine possible damage and inspection priorities immediately following a seismic event.