Analysis of longitudinal pounding due to relative displacement between pier top and girder of continuous girder bridge under input of traveling wave

Based on the characteristics of multispan continuous girder bridges,an analytical model simulating pounding behavior of continuous girder bridge was developed.The parametrical analysis of the pounding phenomenon associated with longitudinal excitation of traveling seismic wave was carried out by using the nonlinear time-history girder analysis method.The results show that the period ratio of adjacent girder has more effect on pounding response of short period segments,the relative displacements between adjacent bridge piers and girders is obviously increased considering the effects of pounding and of traveling seismic waves,which may even cause bridge girder to drop from piers and collapse;The relative displacements between adjacent bridge piers and girders decrease with increase of the coefficient of friction.In order to consider the effects of pounding on the seismic relative displacement responses,the pounding effect amplification factor of the relative displacement between the top of the transitional pier and the girder was introduced;The concept of the pounding effect amplification factor provides a new idea of the anti-girder drop bridge design.