波浪作用下高速列车-轨道-桥梁系统耦合振动研究

Research on Train-Track-Bridge Coupling Vibrations under Wave Forces in High-Speed Railway Bridge

为研究波浪作用对高速铁路跨海桥梁车-轨-桥系统耦合振动的影响,基于线性波浪理论和Morison方程模拟波浪荷载,采用分布力模式输入既有车-轨-桥系统耦合振动分析程序,提出波浪作用下的车-轨-桥系统耦合振动分析方法。以某高速铁路跨海斜拉桥为背景,研究波坡面效应、波浪重现期、车速对车-轨-桥系统动力响应的影响,并评估不同重现期波浪作用下过桥列车的走行性。结果表明:波坡面效应会使作用于不同单桩的波浪荷载初始相位不同,从而导致作用于群桩基础的波浪荷载合力不同;随着波浪重现期的增大,车-轨-桥系统的横向动力响应均增大,而竖向动力响应几乎不变;考虑波浪作用后,列车的行车安全性指标均随车速的增大而增大,波浪荷载会显著降低桥上列车的乘坐舒适性并增加桥上列车的脱轨风险。常遇波浪(10年重现期)和极端波浪(100年重现期)作用下列车的安全车速阈值分别为325 km/h和275 km/h。

The study in this paper focuses on coupling vibrations of high-speed railway trains,tracks and bridge system(TTBS)under wave forces.An analytical method developed on the basis of the linear wave theory and Morison equation,is proposed,in which the coupling vibration analytical program was imported via a distributed force model.Based on an existing high-speed railway sea-crossing cable-stayed bridge,the influential factors,including wave slope effect,wave return period and train speed,were analyzed,and the running behaviors of trains under wave forces of different return periods were evaluated.It is shown that the wind slope effect changes the initial phases of wave forces acting on individual piles,leading to different resultant wave forces acting on the group pile foundation.As the wave return period of waves increases,the lateral dynamic responses of the TTBS become stronger,while the vertical dynamic responses almost keep the same.Taking into account the effect of wave forces,the train running safety indexes are enhanced as the train speed increases,indicating that wave loads can significantly reduce human comfort in the running trains and increase the derailing risk of trains.The safe train running speed thresholds of common wave forces(10-year return period)and extreme wave forces(100-year return period)are 325 km/h and 275 km/h,respectively.