重载铁路路基足尺模型试验研究

以朔黄重载铁路为工程背景,通过构建重载列车模拟加载系统和路基足尺模型,开展路基动力响应试验,分析了在循环加载条件下路基的动力响应特性。试验结果表明,路基中不同深度动应力峰值均随着轴重的增加而增加,轴重越大,动应力的影响深度越大,路基中动应力随深度的增加呈负指数衰减趋势。路肩处动位移峰值随轴重的增加而线性增加。当轴重增加到30 t后,路基达到临界破坏状态,可见按照原朔黄铁路路基建造标准,其最大运行列车轴重约为27 t,如再增加列车轴重,路基需预先采取强化措施。试验结果对建造运行列车模拟加载系统及足尺路基模型具有借鉴参考意义,同时有助于深刻理解列车轴重对路基动力响应特性的影响。

Research on full-scale model test of heavy haul railway subgrade

Based on Shuo-Huang heavy haul railway, dynamic response tests are carried out through establishing the simulated loading system of heavy haul train and full-scale model of heavy haul railway subgrade, the dynamic response characteristics of subgrade subjected to cyclic loadings are analyzed. The result indicates that with increasing axle load the dynamic stress peaks at different depths in the subgrade also increase. The larger the axle load, the greater the depth influenced by dynamic stress. There is negative exponential function between dynamic stress peak and depth in subgrade. With increasing axle load the dynamic displacement peaks at the top surface of sleeper nonlinearly increase. When axle load increases to 30t, the subgrade comes to critical failure state. This shows that by construction standard of Shuo-Huang railway subgrade, the maximum allowable axle load is about 27t, if increasing axle load, strengthening measures should be taken to subgrade preliminarily. The testing results have some reference for establishing simulated loading system of moving train and full-scale subgrade model. Meanwhile, the testing results provide better understanding of the influence of train axle load on the response of subgrade.