多线铁路桥双车交会的风-车-桥耦合振动研究

摘要

为研究风荷载下多线铁路桥双车交会的动力响应,以某六线双层铁路斜拉桥为背景,采用桥梁结构分析软件BANSYS建立有限元模型,对不同双车交会组合进行风-车-桥系统耦合振动分析,计算各工况下车辆和桥梁的动力响应,并研究双车交会横桥向间距、车桥相对位置和风速对车辆和桥梁动力响应的影响.结果表明:双车交会过程中,迎风侧车辆的加速度变化不明显,背风侧车辆的加速度明显变大;双车横桥向间距对背风侧车辆的横向加速度有不同程度的影响,竖向加速度有明显突变;横桥向间距对桥梁的横向位移略有影响,对竖向位移几乎无影响;双车横桥向间距相同时,靠近来流方向车道交会时车辆加速度比远离来流方向车道交会时大;迎风侧车辆的加速度随风速增大而增大;桥梁跨中横向位移随风速增大而变大,竖向位移和扭转角受风速的影响较小.%To study the dynamic responses of the multi-track railway bridge under the meeting of two trains under the wind load,a six-track double-deck railway cable-stayed bridge was taken as an example and the analysis software BANSYS for bridge structures was used to set up the finite element model.The wind-train-bridge coupling vibration of the bridge under the meeting of the two trains of different combinations was analyzed,the dynamic responses of the trains and bridge under different load cases were calculated and the influences of the transverse spacing distances,relative positions of the trains and bridge and the winds speeds on the dynamic responses of the trains and bridge under the meeting of the two trains were studied.The results of the study demonstarte that in course of the meeting of the two trains,the change of the acceleration of the train on the windwrad side is not significant while the change of the acceleration of the train on the leeward side becomes great significantly.The transverse spacing distances of the two trains have the influences of different degrees on the transverse acceleration of the train on the leeward side and the vertical acceleration of the train has significant sudden change.The transverse spacing distances have slight influence on the the transverse displacement of the bridge and almost has no influence on the vertical displacement.When the transverse spaing distances of the two trains are the same,the acceleration of the train on the track close to the the wind direction under the meeting of the two trains is greater than that of the train on the track far from the wind direction.The acceleration of the train on the windward side increases with the increase of the wind speeds and the transverse displacement at the midspan of the bridge becomes great with the increase of the wind speeds,however,the influences of the wind speeds on the vertical displacement and torsion angles are slight.