地铁车辆经过不同轨道结构时对地面振动的影响研究

Influence of Different Track Structures in Metro Systems on the Tunnel and Ground Vibration Characteristics

在列车正常运行条件下对某地铁曲线路段钢弹簧浮置板道床、科隆蛋和普通扣件轨道结构段的隧道壁振动和地面垂向振动进行现场测试,通过时域和频域分析对比地铁经过时不同轨道结构段振动从隧道壁传到地面以及地面垂向振动随距离的传播规律。结果表明:振动从隧道壁传至地面时200Hz^500Hz频段衰减较快,且地面垂向振动主频在100Hz以内,隧道壁振动主频在300Hz以内;钢弹簧浮置板道床和科隆蛋结构段的地面垂向振动随着离开线路中心线距离的增加而减小;在普通扣件结构段距线路中心线30m左右处存在一个振动放大区;列车经过时轨道线正上方0~30m范围内垂向振动的峰值频率主要在40Hz至63Hz。该测试方法和研究结果可为地铁线路设计提供相应参考。

The tunnel wall vibrations and ground vertical vibrations of the steel spring floating slab track(FST),the Cologne egg baseplate track and the ordinary fastener slab track in a subway curved section under the normal operation condition of the train were tested.The propagation characteristics of tunnel wall vibration and the ground vibration against the distance from the track center with different track structures were compared by time and frequency domain analysis.The results show that the vibration of the 200 Hz-500 Hz frequency band attenuates rapidly when the vibration transmits from the tunnel wall to the ground.The ground vertical vibration frequency is within 100 Hz,and the tunnel wall vibration frequency is within 300 Hz.The ground vertical vibration levels of the steel spring floating slab track(FST)and the Cologne egg track structure decrease with the increase of the distance from the track center.There is a vibration amplification zone around 30 m from the center line of the ordinary fastener structure.The peak frequency of the ground vertical vibration in the range of 0~30 m above the track is mainly in 40 Hz-63 Hz range.This test methodology and its results provide a reference for the design of new metro lines.