Performance of a Rigid Frame Arch Bridge under Near-Fault Earthquake Ground Motion

During May 12th 2008 Wenchuan earthquake with the magnitude of 8.0, a 4-span rigid frame arch bridge named as Xiaoyudong Bridge which situated close to the epicenter was hit by strong ground motion and was severely damaged. The earthquake response analysis of the bridge was made using FE software MIDAS based on recorded ground motion during the Wenchuan earthquake in this paper. The study showed that the main and minor arch legs on the both ends piers were weak links which may be damaged firstly under strong ground motion. The next damage at the pier with weakest horizontal stiffness is one of the important reasons causing the bridge collapsed. This paper will introduce our work on those respects and some drawn conclusions.