结合多跨连续梁桥的结构特点,提出了一种能模拟联间碰撞行为的连续梁桥碰撞分析模型。用非线性时程方法对行波输人下连续梁桥的地震碰撞反应进行了参数分析。结果表明:相邻联的周期比对短周期联位移的碰撞效应较大,考虑地震行波输入时伸缩缝处的碰撞效应可能会大幅度增大墩梁的相对位移,从而增大了地震作用下发生落梁的风险;墩梁相对位移随滑动支座摩阻系数的增大而减小。最后提出用一个碰撞效应增大系数来考虑连续梁桥相互碰撞对墩梁相对位移的影响,利用碰撞效应增大系数的概念为连续梁桥防止落梁的设计提供了一个新的思路。
Based on the characteristics of multispan continuous girder bridges, an analytical model simulating poun ding behavior of continuous girder bridge was developed. The parametrical analysis of the pounding phenomenon as sociated with longitudinal excitation of traveling seismic wave was carried out by using the nonlinear timehistory girder analysis method. The results show that the period ratio of adjacent girder has more effect on pounding re sponse 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 displace ment responses, the pounding effect amplification factor of the relative displacement between the top of the transi tional pier and the girder was introduced ; The concept of the pounding effect amplification factor provides a new idea of the antigirder drop bridge design.