考虑桥面初始变形的大跨度斜拉桥车桥耦合振动分析

Analysis of Vehicle-bridge Coupling Vibration of Long-span Cable-stayed Bridge Considering Initial Deformation of Bridge Deck

新建郑州至济南高速铁路山东段黄河特大桥采用预应力混凝土部分斜拉桥体系,桥梁跨度布置为(108+4×216+108)m,设计速度350 km/h。建立列车-桥梁空间振动分析模型,对桥梁的自振特性进行分析,并考虑了长、短波不平顺与温度荷载不同组合工况下桥面初始变形的影响,当列车以不同速度通过时,对列车和桥梁的动力响应进行了评价。计算结果表明:桥梁前2阶振型表现为塔梁横弯,塔梁竖弯相对滞后,而塔梁纵飘出现最晚;当列车分别以设计速度和检算速度通过该桥时,列车与桥梁的动力响应均满足要求,列车乘坐舒适性达到“良好”标准以上;各工况下列车和桥梁的动力响应差异不大,桥面初始变形对车桥耦合振动的影响主要体现在变形幅值上。

The(108+4×216+108)m prestressed concrete partial cable-stayed bridge system is applied on the New Yellow River Super Large Bridge in the Shandong section of Zhengzhou-Jinan high speed railway,with a design speed of 350 km/h.In this paper,the spatial vibration analysis model of the train-bridge was established.The natural vibration characteristics of the bridge were analyzed,and the influence of the initial deformation of the bridge surface under the different combination of the long and short wave irregularity and the temperature load was considered.The dynamic response of the train and the bridge was evaluated when the train passes through at different speeds.The results show that the first two vibration modes of the bridge are the transverse bending of the tower beam,and the vertical bending of the tower beam is relatively lagging,while the longitudinal floating of the tower beam is the latest.When the train passes the bridge at bridge design speed and check speed,the dynamic response of the train and bridge is within the allowable value and the ride comfort of the train reaches above the“good”standard.The dynamic response of the train and the bridge under various working conditions has little difference,and the influence of the initial deformation of the bridge deck on the coupling vibration of the vehicle and bridge is mainly reflected in the deformation amplitude.This research may provide theoretical basis for the smooth development of the project and the design of similar long span railway cable-stayed bridge.