大跨径PC斜拉桥地震响应非线性分析

基于大跨径桥梁地震反应分析方法,建立了斜拉桥动力分析空间有限元模型.考虑了几何非线性对结构动力特性及地震响应的影响,以一座大跨径预应力混凝土斜拉桥为研究对象,采用直接积分法对该桥进行了地震非线性时程分析.根据该桥的方案设计,比较了两种塔梁连接方式下结构的动力特性,分析了桩土作用效应对结构地震响应的影响.计算结果表明:在大跨径斜拉桥抗震设计时,应考虑桩土相互作用的影响;人工拟合地震动和相近场地实测地震动记录的计算结果相差较大,在抗震复核中应取最不利荷载作用.

Nonlinear Analysis of Seismic Respond for Long - span PC Cable - stayed Bridge

Based on long-span bridge seismic analysis method,a spatial finite element model of cable-stayed bridge for dynamical analysis is established in this paper.The time history analysis for a long-span PC cable-stayed bridge is carried out with immediate integration method.The dynamic property and seismic response effects of geometric nonlinearities of the structure are calculated.According to design of the bridge,the difference dynamic property of two tower-girder connection types is compared.With some different seismic loads,the difference seismic response of the structure is compared.Considering pile-soil interaction,the difference seismic response of the structure is analyzed.The result shows that it must be considered pile-soil interaction in the seismic design of long-span cable-stayed bridge.There is a great deal of difference of calculations between the man-made seismic wave and actual seismic record of sites which are of similar environment.The worst loading condition in seismic calculation shall be taken into account.