列车荷载作用下无砟轨道路基动应力特性分析  

Analysis on the Dynamic Stress Characteristics of the Unballsted Track Subgrade under Train Loading

作　　者：刘钢[1] 罗强[1] 张良[1] 陈虎[1] 陈坚[1] 

机构地区：[1]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031

出　　处：《铁道学报》2013年第9期86-93,共8页Journal of the China Railway Society

基　　金：国家自然科学基金(50838006);中央高校基本科研业务费(SWJTU12ZT05);铁道部科技研究开发计划(2010G018)

摘　　要：以现场实测数据为基础,结合理论分析与有限元计算,对列车荷载通过无砟轨道传递到路基面的动应力分布模式及频响特征、动应力沿路基深度的衰减规律等进行讨论,可得出以下结论:(1)无砟轨道具有良好的荷载扩散作用,路基面动应力的一次加卸载过程由1个转向架的2个轴载共同作用完成,并可简化为纵向梯形、横向均匀的分布模式;(2)双轴转向架荷载作用下的动应力沿深度衰减较慢,至基床底部的衰减率约为50%,较实测值偏大约10%;(3)路基面承受的动应力作用频率由列车荷载激振引起,主要受车长及转向架间距控制,转向架轴距对应的频响特征已不明显,最大作用频率约为车长频率的4倍。Taking data measured on site as the basis and combining with theoretical analysis and finite element calculation,referring to the situation when loads of a running train were transmitted from unballasted tracks to subgrade surface,the distribution pattern and frequency response characteristics of dynamic stresses and the attenuation law of dynamic stresses along the subgrade depth were investigated.The following conclusions are drawn：（1） Because unballasted tracks possess good load diffusion effect,one loading and unloading cycle of dynamic stresses on subgrade surface is completed by co-action of two axle loading of one bogie,and it is simplified into distribution of trapezoids in the longitudinal direction and uniform distribution in the lateral direction;（2） dynamic stresses attenuate slowly along the subgrade depth under two-axle loading,and their attenuation rate is decreased to 50％ at the bottom of foundation,about 10％ more than the measured value; （3） the frequencies of dynamic stresses acting on subgrade surface are excited by train loads and are mainly controlled by vehicle lengths and bogie intervals,the frequency response characteristics corresponding to the bogie pitch are gone,and the maximum acting frequency is 4 times the fundamental frequency generated by the vehicle length.

关 键 词：无砟轨道 路基 列车荷载 动应力 频响特征 

分 类 号：U213.1[交通运输工程—道路与铁道工程]