中文摘要：

粗粒土填料作为铁路路基核心层,直接承受行车荷载的反复作用,其在动载反复作用下的变形特性决定了路基工作性能,但目前对粗粒土填料在列车往复作用下的动力变形特性研究不多.为探究行车荷载对基床粗颗粒土动力变形特性的影响规律,进行一系列粗粒土填料持续振动条件下的大型动三轴试验,包括不同动应力幅值（模拟不同列车轴重）、不同围压（模拟不同埋深下的侧压作用）和不同含水率（模拟不同雨水环境）等多种情况.获得路基粗粒土填料的临界动应力和累积应变随围压和含水率变化的系列关系数据和变化规律.试验结果对重载铁路路基核心层的动力变形稳定性评价和基于动力变形控制的路基设计具有重要参考价值.

英文摘要：

Being the material filling the core layer of railway subgrade,coarse-grained soil（CGS） is directly subject to cyclic traffic loading.The operating performance of subgrade depends on the deformation characteristics of the CGS core layer under cyclic loading.However,few researches on CGS＇s dynamic deformation characteristics （DDC） under cyclic action of moving trains are seen currently.In this paper,in order to study the influence law of traffic loading on CGS＇s DDC,a series of large-size dynamic triaxial tests were carried out with different dynamic stress amplitudes（to simulate different axle loads）,different confining pressures（to simulate the effect of lateral pressures at different buried depths） and different water contents（to simulate different rain water environments）.A series of relation data and variation rules were obtained,including the relation of the critical dynamic stress and accumulative strain of CGS subgrade filling with the confining pressure and water content.The results of these tests have important reference value to evaluation of dynamic stress deformation stability of the core layer of heavy-haul railway and to subgrade design based on dynamic deformation control.