MECHANISM OF SEISMIC RESPONSE OF A PC CABLE-STAYED BRIDGE SUBJECTED TO A LONG-PERIOD SEISMIC EXCITATION

In this study, the mechanisms associated with the seismic response of a long-period structure when subjected to a long-period seismic excitation are clarified. A typical scale cable-stayed bridge with prestressed concrete girders (PC cable-stayed bridge) was selected for analysis. First, we simulated long-period components of the ground motion at the site of the Ji-Lu Bridge, which was damaged in the 1999 Chi-Chi, Taiwan earthquake, and the damage of the bridge was assessed by nonlinear seismic analysis using the simulated ground excitations. Second, shaking table tests of a model PC cable-stayed bridge were carried out, in consideration of the similarity law, to clarify the mechanisms involved, focusing on the linear and nonlinear seismic responses of the tower and cables.