Earthquake response of an arch bridge under near-fault ground motions

During the Wenchuan earthquake in 2008, some of the arch bridges in the seismic zone were damaged. To assess the performance of arch bridge under near-fault ground motions, both experimental and numerical studies are conducted in this paper. Firstly, an ambient vibration test of a real typical arch bridge is made to measure the dynamic characteristics of the structure and calibrate the finite-element model. Then the earthquake response of the bridge is made using FE software MIDAS based on recorded ground motion in the Wenchuan earthquake. The study shows that the joint between deck and tie at 1/4 span and 3/4 span, the joint between beam and arch and middle of the beam are weak links under near-fault ground motions.