高速铁路路基不均匀冻胀变形对轮轨系统的动力影响研究

Dynamic Influence of Uneven Frost Heaving Deformation of High-speed Railway Subgrade on Wheel-rail System

基于车辆-轨道耦合动力学理论和有限元方法,开展高速铁路无砟轨道路基不均匀冻胀变形对高速轮轨系统的动力学影响研究,分析不同程度的路基不均匀冻胀变形对高速车辆-轨道耦合系统振动响应的影响规律。研究结果表明:路基的不均匀冻胀变形会加剧轮轨动态相互作用,对行车安全性和乘车舒适性产生不良影响,同时易引起较强的轨道结构振动,进而影响轨道结构的长期服役性能;随着路基不均匀冻胀变形波长的减小和冻胀变形幅值的增大,高速车辆-轨道耦合系统的垂向振动动力学指标均出现增大趋势,研究发现应重点关注波长20 m以内的路基不均匀冻胀变形及其幅值的增大;对于路基不均匀冻胀变形较严重地段,可通过适当降低车辆的运行速度,以有效降低轮轨系统的动态相互作用,从而减小路基不均匀冻胀变形对高速行车安全性的影响,但是,限速措施对于改善高速乘车舒适性的效果并不明显。

Based on the vehicle-track coupling dynamics theory and the finite element method, the dynamic influence of uneven frost heaving deformation of ballastless track subgrade of high-speed railway on the high-speed wheel-rail system was investigated and the influence of different degrees of uneven subgrade frost heaving deformation on the vibration response of the high-speed vehicle-track coupling system was analyzed. The results show that the uneven frost heave deformation of subgrade will aggravate the wheel-rail dynamic interaction, affect the running safety and ride comfort of high-speed trains, and cause strong vibration of track structure, which will affect the long-term service performance of the track structure. With the decrease of the wavelength and increase of the amplitude of uneven frost heaving deformation, the vertical vibration dynamic indexes of the high-speed vehicle-track coupling system show an increasing trend. The uneven subgrade frost heaving deformation with wavelength less than 20 m and the increase of its amplitude should be paid close attention to. For the sections with serious uneven subgrade frost heaving deformation, the wheel-rail dynamic interaction can be effectively alleviated by reducing the train running speed, so as to reduce the impact of uneven subgrade frost heaving deformation on the running safety and track vibrations. However, the reduction of train running speed has minor effect on improving the ride comfort of high-speed train.