Earthquake response of bridges bearing on flexible rubber considering pounding of girders

To make clear the influence of the girder pounding during earthquake, nonlinear dynamic analysis was used to investigate the behavior of the impact between girders supported on flexible rubber bearings. A non-continuous bridge of two equal spans supported on flexible rubber bearings was employed. Effects such as those of the compression stiffness of the impact spring, time intervals in computation of impact, seismic wave of ground, relative period of two adjacent beams, etc. were discussed. The results showed that when the earthquake leads to significant impact forces between the girders, the horizontal displacement of the super structures is no larger than that of no impact between two girders. The girder pounding occurred with head-on direction mainly. Therefore, the possibility of the girder falling induced by the impact is small if the rubber bearings work well. It was also found that buffer element between girders can reduce the impact force, but can't prevent the girders falling.