DAMAGE ANALYSIS OF A BRIDGE AFFECTED BY THE CHI-CHI EARTHQUAKE

Abstract

Seismic damage analysis was conducted on the Chang-Geng Bridge damaged in the 1999 Chi-Chi Earthquake in Taiwan. This bridge sustained peculiar damage that two girders fell to the ground even though the ground did not show any fault displacement. The cause of the fall was assumed to be the horizontal displacement of the girders when they collided under seismic loading. Through nonlinear dynamic analysis using field measurement results and detailed drawings obtained from the administrator of the bridge, it was confirmed that the girders were pushed toward the parapet and collided from the back under seismic loading, resulting in the fall from the piers.