Pounding Analysis of Isolated Girder Bridge under Nonpulse and Pulse-Like Earthquakes

Abstract

Pounding damages are frequently encountered in concrete continuous girder bridges during strong earthquakes. In the evaluation of pounding responses, the simplified lumped mass model with the contact element are usually adopted. However, the pounding responses calculated based on the simplified model are often significantly different from the real results, because the simplified model fails to consider the details of pounding processes and ignores concrete damage. In addition, the seismic parameters (e.g., peak ground acceleration, peak ground velocity) affects the pounding responses greatly. To further enhance the aforementioned considerations, this study presents the longitudinal pounding analysis of an isolated continuous girder bridge subjected to the unidirectional ground motions based on a multiscale simulation scheme. The pounding between the bridge and side abutments was simulated with a contact algorithm, and the concrete damages were considered. Thirty-three nonpulse and thirty-three pulse-like real ground motions were selected as seismic excitations to investigate the effects of seismic properties on pounding responses. Two pounding patterns were recognized and found to be related to the V-shaped velocity segment of the seismic input. Correlation coefficient and semipartial correlation coefficient were used to analyze the relationship between the seismic parameters and corresponding pounding responses.