中文摘要：

为了更准确研究高速列车引起的地基振动,提出了车体—轨道系统—饱和土地基耦合分析模型。列车荷载分为两部分：车体轴重和轨道不平顺引起的轮轨动力作用力。车体模拟为一个多刚体系统,并在轮对与轨道之间引入Hertizian线性接触模型来考虑轮轨的动力相互作用。通过车体轮对与轨道接触点位移协调条件,求得轨道不平顺等因素引起的轮轨动力作用力。在忽略土颗粒压缩性与自重的情况下,饱和土体中引入Biot波动理论来描述其动力特性。轨道系统与土体控制方程通过Fourier变换在变换域里进行求解,时域数值结果通过快速Fourier逆变换（IFFT）求得。研究了轮轨激振频率对轮轨动力作用力的影响以及在列车轴重与轮轨动力作用力作用下饱和土体的动力响应,表明轮轨动力作用力对列车荷载引起的周边环境振动有着重要影响,在实际工程中不能忽略。

英文摘要：

In order to investigate the train-induced ground vibration more accurately,a vehicle-track-ground coupling model is proposed.The source of vibration excitation is divided into two components： the axle load and the roughness-induced dynamic loads.The vehicle is simulated by a multi-rigid-body system and a Hertizian contact spring is introduced between each wheelset and the rail to consider the dynamic wheel-rail forces.Compatibility of the displacements at wheel-rail contact points yields equations for the dynamic wheel-rail loads.The Biot’s full dynamic poroelastic theory is employed for the saturated half-space,neglecting the body force and the compressibility of solid grain.The governing equations are solved by using the Fourier transform in the transformed domain.The results in time domain are obtained by applying the inverse fast Fourier transform（IFFT）.The dynamic wheel-rail force is investigated for various exciting frequencies,and the dynamic response of the poroelastic half-space induced by both the axle load and dynamic load is presented.It is concluded that the dynamic load makes important contribution to train-induced environment vibration and can not be neglected in the engineering practice.