高速铁路路基动力响应特性

Dynamic response performance of high speed railway subgrade

结合高速铁路路基基床动力响应现场实测与有限元计算,分析了无砟轨道路基动应力、动变形和振动加速度的幅值特征及变化规律,揭示了列车荷载作用下基床内应力、应变的分布规律。研究结果表明：轨道路基基床动应力范围为11-16 kPa,随车速变化不明显,随轴重增大而增加,每1 t轴重产生动应力约为1.02 kPa;无砟轨道路基基床表面动应力分布范围较大且相对均匀,动应力随深度衰减较缓慢;无砟轨道路基动变形较小,随着路基刚度的增大动变形减小且分布较均匀,路基对线路整体刚度影响不大;无砟轨道路基振动加速度一般不大于10 m/s^2,振动主频100-500 Hz。

Combining field test and finite element calculation of high speed railway subgrade bed dynamic response,this paper analyzed the amplitude characteristics and change laws of ballastless track subgrade dynamic stress,dynamic deformation and vibration acceleration and revealed the distribution regularities of subgrade bed stress and strain under train load.The research results showed that dynamic stress of track subgrade bed is 11 -16 kPa,which changes little with the speed changing and increases with the increase of axle load,each 1 t axle load produces dynamic stress that is 1.02 kPa,the surface dynamic stress distribution range of ballastless track subgrade bed is wide and relatively uniform,dynamic stress decreases slowly with depth increasing,dynamic deformation of ballastless track subgrade is little,dynamic deformation decreases and its distribution is uniform with the increase of the subgrade rigidity,which means the subgrade has little effect on the whole line rigidity,vibration acceleration of ballastless track subgrade is generally not more than 10 m/s^2 and vibration basic frequency is 100-500 Hz.