列车循环荷载作用下高速铁路路基累积变形预测方法

A method for predicting the cumulative deformation of high-speed railway subgrades under cyclic train loads

随着高速铁路的兴建,对土质路基在循环荷载作用下的累积变形和破坏的研究越来越显得重要。基于三维有限元轨道/路基动力系统模型,计算得到列车动荷载作用下路基沿深度分布的动偏应力,然后结合LiD.Q.和Selig提出的路基土累积塑性应变模型来预测长期列车循环荷载作用下土质路基的累积变形。根据现场动载试验段的土性参数和试验条件下路基沿深度方向的动偏应力进行累积变形预测,预测结果与激振试验结果基本相符,从而验证了预测模型参数选择的有效性。然后对高速铁路无砟轨道路基进行累积变形预测,为建立无砟轨道路基累积变形的计算方法提供参考。

The analysis of subgrade cumulative deformation under repeated moving loads on high-speed railways is of the great importance. The 3-D consistent viscous-spring artificial boundaries and viscous-spring boundary elements are introduced in the ABAQUS software to model soil vibrations due to high-speed trains on ballast/ballastless track/ subgrade. The distribution of subgrade dynamic deviatory stress is obtained. A method is developed for determining the parameters of the predictive model presented by Li D. Q. and Selig. E. T for subgrade cumulative strain, which takes into account of the influence of the number of load cycles, stress state, soil type and physical state. Field measured data and the simulation results are in good agreement.