中文摘要：

将无砟轨道路基结构简化成双层弹性体系，基于层状弹性体系力学理论，给出无砟轨道路基面支承刚度的计算方法。应用该方法进行遂渝线无砟轨道试验段路基面刚度计算，并与现场加载试验测试结果进行比较，两者吻合较好，验证了该方法的可行性。以桥梁路基过渡段为例，将此计算方法应用于无砟轨道典型过渡段的动力性能评估中，进行动力计算。结果表明，该桥梁路基过渡段的钢轨挠度变化率小于0．3mm·m^-1的限值，满足行车要求。运用该计算方法对无砟轨道基床表层及底层变形模量Ev2的合理取值进行研究，结果表明：改变基床表层变形模量对路基面支承刚度影响不大，而改变基床底层变形模量对路基面支承刚度的影响明显；将变形模量Ev2作为压实标准时，对于基床表层和底层，Ev2可分别取为120-260和80～140MPa。

英文摘要：

The subgrade structure of ballastless track was simplified to an elastic two-layer system and the calculation method of the supporting stiffness of the subgrade surface in ballastless track was given based on the mechanical theory in elastic layered system. The method was used to calculate the supporting stiffness of the subgrade surface in the ballastless track test section of Suining-Chongqing Railway line. The method was validated to be feasible by comparing the calculation results with those of the on site loading test. Both results agreed well. The method was also used to investigate the dynamic performances of the typical transition section of the ballastless track, and the dynamic calculation was taken with bridge-subgrade transition section as an example. The calculated results indicate that the change rate of the deflection of rail is less than 0.3 mm·m^-1 , which meets the requirement for train operation. Furthermore, the reasonable value of the deformation modulus Ev2 of the surface layer and the bottom layer of the bedding in ballastless track was studied by using this method. The results show that the change of the deformation modulus of the surface layer of the bedding has little effect on the Supporting stiffness of the subgrade surface, while the effect of the deformation modulus of the bottom layer of the bedding is obvious. The deformation modulus Ev2 of the surface layer and the bottom layer of the bedding is respectively 120-260 MPa and 80-140 MPa, when it is taken as the compaction standard.