交叠线路地铁列车引起的环境振动分析

南昌地铁1、2号线交汇于八一广场,形成上下交叠地铁线路。由于交叠线路的列车同时运行的组合情况较多且引起的环境振动比单线大,因此有必要在交叠线路设计阶段对具体工程进行环境振动分析。通过建立包含4孔交叠隧道的轨道-隧道-大地三维有限元模型,分析列车荷载作用下大地的振动响应。研究结果表明:环境振动主要受埋深较浅的2号线影响;对2号线采取减振措施最为经济合理;交叠地铁线路列车同时运行时地面会出现多处振动加强区,均出现在线路交汇处和距线路中心40 m处附近。

Analysis of Environmental Vibration Induced by Subway Trains on Overlapping Lines

Nanchang subway Line 1 and Line 2 meet at Bayi Square,where the metro lines are overlapped.Because of the complex combination situation of the overlapping lines,in the design phase,the vibration must be analysed in combination with specific engineering conditions.In this paper,a 3D finite element model of rail-tunnel-ground is established with four o-verlapping tunnels,and the ground vibration responses are ana-lyzed under the function of train load.The study shows that environmental vibration is mainly affected by Line 2 which was built with shallow depth,but it is also the most economical and reasonable way to take vibration reduction measures on this line.Several vibration strengthening areas are found on ground surface when metro trains on the overlapping linesare in simul-taneous operation,the strengthening area all exist at the inter-sections and in areas about 40 m away from the line center.