地震作用对钢桁梁桥车桥系统耦合振动的影响分析  

Coupled vibration of train-bridge system of steel truss bridge with seismic effect

作　　者：邓子铭[1] 郭向荣[1] 张志勇[1] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2011年第1期184-191,共8页Journal of Central South University:Science and Technology

基　　金：铁道部科技发展计划项目(2009GD029)

摘　　要：为了研究地震对车桥系统耦合振动的影响,采用最小二乘法对地震加速度进行校正拟合,消除位移时程因直接对加速度时程积分出现的漂移现象。根据弹性系统动力学总势能不变值原理及形成矩阵的"对号入座"法则,将轨道不平顺作为系统的自激激励源,地震作为外部激励,建立考虑地震作用的车桥系统耦合振动方程。并以某钢桁梁桥为例,采用计算机模拟的方法,建立列车和桥梁动力分析的有限元模型,研究地震对车桥系统耦合振动的影响。研究结果表明:在地震作用下,桥梁的动力响应主要取决于地震力,横向地震波对车辆与桥梁的横向动力响应具有非常重要的影响;竖向地震波主要影响车桥系统的竖向振动,对横向振动影响很小;但是,竖向地震波对脱轨系数、轮重减载率、车体竖向加速度的影响较显著,因此,在评判桥上列车的运行安全性时必须考虑竖向地震波的影响。In order to study the effect of coupling vibration of train-bridge system on earthquake response, using the least squares method to correct and fit the seismic acceleration, the drift phenomenon of displacement time histories caused by the direct integration of acceleration time history was eliminated. In addition, according to the principle of total potential energy with stationary value in elastic system dynamics and the ＂set in right position＂ rule for formulating system matrixes, and taking the track irregularities as system＇s self-excitation source with the seismic as external excitation, the coupling vibration equation of train-bridge system considering the seismic excitation was built up. Taking a steel truss girder as an example and using the computer simulation method to establish the dynamic model of train-bridge system, the effect of coupling vibration of train-bridge system on earthquake response was researched. The results show that the dynamic response of the bridge depends primarily on the size of the earthquake, the transverse seismic wave has important impact on the transverse dynamic response of vehicles and bridges, the vertical seismic wave has a major impact on the vertical vibration of the vehicle-bridge system but with little effect on the transverse vibration. However, the influence of the vertical seismic wave on the derailment coefficient, the load decrement rate of wheel mass and the vertical acceleration are so significant that the impact of vertical seismic wave in judging the safety of trains must be considered.

关 键 词：钢桁梁桥 地震加速度 漂移现象 耦合振动 有限元模型 动力响应 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]