Seismic Performance of Retrofitted Reinforced Concrete Bridge Pier

Abstract

This paper presents the experimental testing of a bridge pier for seismic performance. A half-scale model of a typical bent in the Bay Area Rapid Transit's (BART's) West Oakland Aerial Guideway was investigated. Two pseudo-cyclic bidirectional tests were conducted on a single test specimen that modeled an existing pier including proposed retrofit measures. Twenty-four battered piles provided the foundation moment capacity during a system test. This test was designed to test the failure mechanism of the pile-pile cap connection. Another test isolated the column-footing joint by restraining the pile cap rotation and translation. A retrofitted pile cap was examined for its joint shear response. The test results showed a limited system ductility after pile failure, followed by a rocking movement from the pier. Results from the joint shear test indicated the retrofit could prevent joint shear failure and established the allowable column-footing joint shear stress to use in retrofit design.