列车荷载作用下路基结构动力响应分析

针对秦沈客运专线场地条件，采用有限元-无限元相结合的手段，建立列车荷载作用下路基结构动力反应的有限元数值模型，分析了列车荷载作用下，路基动力响应的分布规律，并探讨了列车速度对路基振动反应的影响规律。结果表明:路基土中竖向动应力幅值随深度增加而迅速衰减；随着列车速度的增加，路基顶面的动应力幅值呈增加趋势；列车荷载对轨道路基的影响主要体现在基床部位，因此对于高速铁路需要对其进行加强。所得结论，为铁路路基设计和加固提供了理论依据。

Analysis on Dynamic Response of Subgrade Structure under Action of Train Load

In relation to the field conditions of Qinhuangdao-Shenyang PDL, the finite element model for dynamic response of subgrade structure under action of train load was established by the way of combined finite- infinite element, through which the law of distribution of this dynamic response was analyzed and then the law of effect of train speed on this dynamic response was discussed. The results show that the magnitude of vertical dynamic stress in subgrade soil decreases rapidly with increase of the depth; as train speed increases, the magnitude of the dynamic stress on the top of subgrade presents certain increment; the effect of train load on track subgrade is reflected at the bed mainly; therefore, for high-speed railway the subgrade is required to be reinforced. The conclusion obtained offers theoretical basis for design and reinforcement of railway subgrade.