Full-Scale Pseudo-Dynamic Test for Bridge Retrofitted With Seismic Isolations

Abstract

This paper presents the performance of a retrofitted bridge with a seismic isolation. To validate the seismic performance of retrofitted bridge experimentally, four full-scale reinforced concrete bridge piers with fixed support conditions were fabricated and tested. Several different bearing systems were installed and a static vertical load was applied to the top of the bearing to simulate the dead load of superstructure. In addition to rubber bearing (RB) and lead rubber bearing (LRB) systems, conventional pot bearing was also considered. Using a pseudo-dynamic testing method, a horizontal loading was applied to the specimen to simulate the earthquake loading. The seismic response of isolated specimens with the RB, and LRB systems were compared with that of the specimen with conventional pot bearing. The results showed that a seismic isolation system considered in this study was effective in reducing the magnitude of the forces transferred to the substructure and in shifting the period of the bridge. The LRB system can effectively reduce the peak acceleration transmitted to the structure, which is less than those with RB system under the earthquake loading. By the test results it can be concluded that the proposed seismic retrofit method was found to be valid.