长周期随机地震作用下大跨斜拉桥局部场地效应分析

Local Site Effect Analysis of Long-span Cable-stayed Bridge under Long-period Stochastic Seismic Excitation

为了考察长周期随机地震作用下局部场地效应对大跨斜拉桥结构响应的影响,借助ANSYS有限元软件,建立了某大跨斜拉桥三维模型,采用改进虚拟激励法,对其进行了考虑局部场地效应的非一致地震响应分析,并与一致激励作对比。结果表明:长周期地震动下局部场地效应对结构内力及位移存在一定的影响,其影响程度及规律随着所处部位的不同而有所区别。

To investigate the influence of local site effect on structural response of a long - span cable - stayed bridge under long - period earthquake motions, the thee - dimensional model of some long - span cable - stayed bridge is established in ANSYS. Then a non - uniform earthquake response analysis of the bridge under local site effect is performed using improved pseudo - excitation, and it is comparatively analyzed with the response under uniform excitation. Results show that the internal force and displacement are influenced to some extent by local site effect, in addition the impact and the rules vary at different sites.