中文摘要：

研究目的：路基作为高速铁路无砟轨道结构的基础,承受列车通过扣件和轨道系统自上而下传来的荷载,扣件分配的荷载大小直接影响着路基内部应力水平。因此,本文通过建立高速铁路无砟轨道路基结构有限元模型,对扣件的荷载分配以及路基内部的应力变化进行研究。研究结论：通过对高速铁路无砟轨道路基结构研究得出：（1）当单轮轴荷载作用于无砟轨道扣件点位置时,荷载主要由7个扣件分配,不同扣件间距和刚度对作用点荷载分配比率影响较大;（2）双轮轴荷载其中一轮轴作用在无砟轨道扣件点位置时,荷载主要由11个扣件分配;（3）距离路基表面距离越远,应力衰减越慢,当应力传递至路基底层时,不同轴重下的路基应力几乎接近;（4）该研究成果可为我国高速铁路无砟轨道路基结构设计提供参考依据。

英文摘要：

Research purposes： As the basis of the ballastless track structure of the high-speed railway,the subgrade is subjected to the train loads transferred from the fasteners and the track system.The internal stress level of the subgrade is directly influenced by the loads distributed by the fasteners.Therefore,the finite element model for the ballastless track subgrade system of the high-speed railway was established to investigate the load distribution of the fasteners and the variation of the subgrade internal stress.Research conclusions： Regarding the ballastless track subgrade structure of the high-speed railway,the following conclusions can be drawn：（1） When the single wheel axle load is acting on the fastener point of the ballastless track system,the load is mainly distributed by 7 fasteners.The load distribution is greatly affected by the space and the stiffness of the fasteners.（2） As for the two wheel system,if one of the wheel axle loads is acting on the fastener point of the ballastless track system,the load is mainly distributed by 11 fasteners.（3） The stress attenuation is slower with the further distance from the subgrade surface.When stress is transferred to the bottom of the subgrade,the subgrade stresses become very close with different axle loads.（4） This research results could provide references for the design of the ballastless track subgrade system of the high-speed railway in China.