桁宽对大跨度铁路斜拉桥车-桥耦合振动性能的影响研究

为考虑桁宽对大跨度铁路斜拉桥动力特性及车辆走行性的影响,以某主跨580m双塔斜拉桥为背景,分别建立了3种不同桁宽(15,24,30m)桥梁的有限元模型,对比其固有频率的差异,并通过车-桥耦合振动分析,比较了3种桁宽情况下桥梁、列车的动态响应。分析结果表明,桥梁横向振动和扭转振动的频率随桁宽的增加而明显增大,竖向振动频率随桁宽的增加而略有减小;主梁的横向位移随桁宽的增加而明显变小,桁宽15m出现了规律性的横向振动;3种桁宽情况下车辆响应变化不明显,桁宽15m时动车和拖车的响应(特别是轮轴横向力及减载率)总体上较其他2种桁宽的响应略大,车辆的响应对桁架的宽度变化不敏感。

Study of Influence of Truss Width on Train-Bridge Coupling Vibration of Long Span Railway Steel Truss Girder Cable-Stayed Bridge

To investigate the influence of truss width on the dynamic and train traveling performance of long span railway steel truss girder cable-stayed bridge,a double-pylon cable-stayed bridge of such type with a main span 580 m was cited as an example,the finite element models for the bridge having three kinds of different truss width(15 m,24 m and 30 m) were respectively built,the differences of natural vibration frequencies of the models were compared and after analysis of the train-bridge coupling vibration,the dynamic responses of the bridge and train under the three kinds of the truss width were acquired.The results of the analysis show that the lateral and torsional vibration frequencies of the bridge significantly increase while the vertical vibration frequency slightly decreases with the increase of the truss width and the lateral displacement of the main girder becomes significantly less with the increase of the truss width.When the truss width is 15 m,the regular lateral vibration occurs and the changes of the train responses under the three kinds of the truss width are not significant.When the truss width is 15 m,the responses of the motorized car and trailer(particularly the wheel axle lateral force and load reducing ratio) are generally slightly greater than those of the other two kinds of the truss width and the train responses are not sensitive to the changes of the truss width.