Theoretical investigation of vertical pounding phenomenon between girder and support under near-fault vertical ground motions

摘要

Recent investigations have indicated that vertical pounding phenomenon between the girder and the support may take place when the bridge structures under severe vertical ground motions. However, the pounding phenomenon of bridges excited by vertical ground motion is rarely studied. The aim of this paper is to investigate the vertical multiple pounding phenomenon of bridge under near-fault vertical ground motions. In the present study, the pounding times and the maximum pounding force are calculated. The effects of seismic excitation period and amplitude on vertical multiple pounding phenomenon are investigated. The numerical results show that for a particular vertical seismic excitation period, only when vertical seismic amplitude reaches a certain magnitude, the bridge structure will appear vertical pounding phenomenon. The pounding phenomenon is underestimated in short period and overestimated in long period by using most of current engineering guidelines.