News Release

Large-Scale Bridge Test to Validate Cost-Effective Construction Technique

Pre-cast segmental construction similar to technique being used in new San Francisco Oakland Bay Bridge

Pre-cast segmental bridge test set-up at the UCSD Powell Research Laboratories.

Components for the San Francisco Oakland Bay Bridge East Span currently being stored at Stockton, California.

San Diego,  Friday, June 11, 2004--UCSD Jacobs School of Engineering structural engineers today performed large-scale seismic tests on a 50 foot-long, 20 foot-high and 14 foot-wide bridge to gauge how it would respond in an earthquake.  The bridge superstructure is made with a pre-cast segmental construction technique similar to the design of the Skyway portion of the new San Francisco Oakland Bay Bridge East Span.  Unlike traditional “cast-in-place” designs, this approach uses pre-cast concrete sections which are held together by strong steel tendons.  Because the deck pieces can be manufactured elsewhere and then fastened to concrete columns upon arrival, they offer an economical solution to bridge construction, especially over deep valleys and waterways. 

Although pre-cast segmental bridge construction has been used in Europe and some parts of the United States for several decades, it has not been used widely applied in earthquake-prone zones such as California because there has previously little research to regarding how it would perform in an earthquake.

The tests taking place at UCSD are part of a full-system test on a 50% scale bridge. and represent the final proof of concept test in a five-year testing program conducted with the American Segmental Bridge Institute and supported by the California Department of Transportation.

The UCSD Jacobs School of Engineering test is focusing on the joints at the tops of the supporting columns which connect to the bridge deck.  These joints have been designed to suffer intentional, targeted damage in order to dissipate energy and ensure the safety and continued operation of the overall structure after an earthquake.  During the tests, approximately 150,000 pounds of force pushes the bridge back and forth over a span of about eight inches.  This slow-motion pseudodynamic test simulates the movements and forces that would be applied to such a bridge during an actual earthquake. The large-scale seismic bridge test will continue over the next several weeks.

Dean Frieder Seible talks about the final stage of testing for the construction technique used on the new East Span of the Bay Bridge. Length: 4:25	Structural engineering professor Jose Restrepo discusses technical aspects of the bridge testing and how the results will be analyzed. Length: 2:21	Kelly Burnell, a Ph.D. candidate, talks about his role in managing the shake test and why UCSD is attractive to graduate students. Length: 4:09
Majid Madani, senior bridge engineer for Caltrans, discusses why the agency is sponsoring the Powell Labs tests. Length: 1:27	Cliff Freyermuth, executive director of the American Segmental Bridge Institute, explains the origins of the program. Length: 1:32

Media Contacts

Denine Hagen
Jacobs School of Engineering
858-534-2920
dhagen@ucsd.edu