CCEER-92-9: Effect of Hinge Restrainers on the Response of the Madrone Drive Undercrossing During the Loma Prieta Earthquake

Abstract

One of the most common seismic retrofitting techniques employed by the California Department of Transportation in recent years is the use of longitudinal restrainer cable systems. The Madrone Drive Undercrossing was retrofitted in 1985 with restrainer cables at the intermediate hinges and concrete shear keys at the abutments.

The October 1989 Loma Prieta earthquake caused extensive damage in the San Francisco Bay Area. Ground acceleration at the Madrone Drive Undercrossing was estimated at 0.65-g. This report describes the computer earthquake analysis conducted to determine the effect of the restrainer cables on the bridge's response.

Analysis cases examined include models with restrainer cables and without restrainer cables. Comparison of the results is made which provides an indication of the performance of the cables (Abstract by authors).