河东长江大桥抗震性能研究

Study on Seismic Performance of Hedong Yangtze River Bridge

以四川省泸州市河东长江大桥为研究对象,对其开展抗震性能研究。首先采用Midas civil建立桥梁三维有限元动力分析模型,斜拉索模拟为空间桁架单元,其余构件都模拟为梁单元。为模拟主塔和墩柱下部的桩—土相互作用,用集中质量法将桩—土离散为质量—弹簧—阻尼系统,其中等代土弹簧单元的刚度采用m法确定。根据设计资料及现行规范,确定其场地的地震动参数并生成相应的反应谱,再根据反应谱拟合出有效的加速度时程曲线。建模计算得到桥梁结构的地震动响应,由结果可知各截面强度均满足性能目标要求。

This paper takes the Hedong Yangtze River Bridge in Luzhou City,Sichuan Province as the research object,and conducts research on its seismic performance.Firstly,the three-dimensional finite element dynamic analysis model of the bridge was established by Midas civil.The cable was simulated as a space truss unit,and the other components were simulated as beam elements.In order to simulate the pile-soil interaction between the main tower and the lower part of the pier,the pile-soil is discretized into a mass-spring-damping system by the lumped mass method,and the stiffness of the equivalent earth spring unit is determined by the m method.According to the design data and the current specifications,the ground motion parameters of the site are determined and the corresponding response spectrum is generated,and the effective acceleration time history curve is fitted according to the response spectrum.The ground motion response of the bridge structure is obtained by modeling and calculation.It is known from the results that the strength of each section meets the performance target requirements.