大跨度悬索桥地震行波效应分析

Analysis of Travelling Wave Effects on Large Span Suspension Bridge

大跨度悬索桥由于各墩柱基础所处地质条件的差异,不同墩柱间的地震动输入存在时间差,结构考虑了行波效应的地震响应可能与一致激励得到的不同。为了研究大跨度悬索桥的行波效应,以某长江大桥为研究对象,分别采用一致激励和非一致激励地震动时程输入,分析结果表明,在不同视波速时结构内力变化不太显著,但对梁端纵向位移较为敏感,相比在一致激励作用下,考虑了行波效应的结构地震响应较小。

Due to various site conditions,seismic responses of large span suspension bridges at non-uniform seismic excitations at the piers are probably different to those responses at uniform excitation.This paper conducts a analysis of travelling wave effects on a suspension bridge on the Yangtze river.By using time history ground accelerations,the corresponding results show that it has least impact on the internal forces.Nevertheless,it is rather sensitive to displacements of bridge deck at various apparent wave velocity.In comparison with seismic responses by uniform excitation,the results with travelling wave effects are less.