高低不平顺条件下高速铁路桥-隧过渡段路基的动力特性

基于D'Alembert原理的能量弱变分和整体Lagrange格式,建立了无碴轨道桥-隧过渡段半无限三维空间动力有限元计算模型,结合高速车辆振动的几何不平顺条件,采用一与不平顺管理标准相应的激振力来模拟列车高速移动的竖向动荷载.通过数值分析,研究了高速移动荷载和不平顺条件下桥-隧过渡段路基的动态响应,揭示了几何竖向上"凸"或下"凹"不平顺等因素对其路基变形、动应力及加速度的影响规律,并与部分实测资料进行了对比,证实了计算模型的正确性.合理选择"超高"填筑过渡段,能减小过渡段路基动态响应,其研究结果为高速铁路过渡段的设计与施工提供了重要基础.

Dynamic performance on high speed railway bridge-tunnel transition section in geometric vertical irregular condition

A analysis model of semi-infinite tri-dimensional spatial finite elements was established for the slab track bridge-tunnel transition system based on weak variational form of the equilibrium equations for the transitional section in D'Alembert method and whole Lagrangian form.Started with the geometric vertical irregularity which causes the vehicle dynamics,an exciting force corresponding with the administered standard of irregularity was used to simulate the vertical dynamic load of the train.Using non-linear numerical analyses,the dynamic response of the subgrade of the transition was researched under vertical high speed moving load and geometric irregular condition,and the influence law was revealed by which geometric vertical convex or cave irregularities changes of the slab track cause the deformation,the dynamic stress and the acceleration of the transitional section.In some concerned parties,The results show that the calculated results agree well with the measured results.A design idea is advanced that "excess height"of the roadbed can reduce the differential settlement and the dynamic response of the transitional section roadbed,the study provides an important basis for the design and construction of the transition section roadbed of express raidway.