高速铁路运行引发场地振动的空沟隔振分析

Open trench isolation of site vibration induced by high-speed railway operation

为研究高速列车作用下,层状地基中空沟对场地振动的隔振效果,基于车辆-轨道耦合动力学理论及有限元法,对建立完善高速车辆-无砟轨道-地基耦合系统动力学模型进行仿真计算,分析设置空沟对场地振动的影响,并探讨了空沟的深度、位置、宽度以及列车速度的影响。结果表明:设置空沟加强了沟前场地的振动,但可使空沟后方地基的竖向和水平振动水平大幅减小,但在特定位置存在振动放大区,引起隔振效果减弱;过浅或过深的空沟均不能达到最优隔振效果;对于在线路旁需要特殊隔振的场地,存在一个适用于其本身的空沟最佳位置;空沟的宽度对隔振效果无明显影响;空沟对更高速度运行列车引起场地竖向和横向振动的隔振效果更明显。

To study the vibration isolation effect of the open trench in layered foundation under the action of high-speed trains,a perfect dynamic model of high-speed vehicle-ballastless track-foundation coupling system was built based on the vehicle-track interaction theory and the finite element method.The effects of the depth,position,width of open trench on the site vibration were discussed,as well as the train speed.The results showed that the site vibration in front of the open trench was enhanced,while the vertical and horizontal vibration behind the open trench was greatly reduced.However,a vibration amplification area located at a specific position weakens the vibration isolation effect.The optimal vibration isolation effect can not be achieved if the open trench is too shallow or too deep.The width of open trench has no obvious effect on the vibration isolation.For the vertical and horizontal vibration of the site caused by higher speed trains,the vibration isolation effect of open trench is more obvious.