列车移动荷载引起的地基土应力状态变化

摘要

The travelling load of train should be simplif ied as a plurality of wheel-axle loads,and the moving process of a train on the track subgrade structure was simulated by multi-point loading.Taking the subgrade structure of slab ballastless track in Suining-Chongqing railway as an object, a three-dimensional dynamic analysis model of track-subgrade-site was established by applying FLAC 3D, the dynamic response of track and subgrade structure was analyzed,and the rotation of stress path and principal stress axis of foundation soil elements beneath the action line during the travelling of train load was studied in detail.The results show that the dynamic response of foundation soil elements has obvious cycle characteristics in theaction of a plurality of wheel-axle loads, and the main stress axis always rotates in a clockwise direction,which rotates 180 degrees continuously.%将列车移动荷载简化为多组轮轴荷载,通过多点加载模拟列车在轨道路基结构上的移动过程.以遂渝线板式无砟轨道路基结构为对象,应用FLAC 3D软件建立轨道-路基-场地三维动力分析模型,对轨道、路基结构的动力响应进行分析,细致分析了列车荷载移动过程中作用线正下方地基中土单元的应力路径和主应力轴的旋转现象.结果表明:地基土单元动力响应具有明显循环特征;主应力轴始终沿顺时针方向旋转,且连续旋转了180°.