摘要
减振垫轨道是城市轨道交通高等减振措施中常用的一种轨道结构。为了研究减振垫轨道结构对车致环境振动的影响,首先对减振垫轨道的模态进行分析,其次建立了地铁列车-减振垫轨道-隧道-土体-建筑物系统模型。该系统模型分为两个子模型,将子模型1中的竖向轮轨力作为子模型2的外加激励,计算分析了轨道板、隧道壁、地面和楼层的车致振动加速度特性与振级特性。研究结果表明:由列车运营引起的振动在传递途径中,竖向振动加速度由轨道板到隧道壁的衰减量远大于由隧道壁到地面的衰减量,楼层和地面的竖向振动加速度水平基本相当;轨道板、隧道壁、地面和楼层的1/3倍频程加速度级两个峰值对应的中心频率31.5 Hz、80 Hz与轨道板第5阶、第10阶主振型的固有频率有关;减振垫轨道的中心频率介于3.15 Hz和8 Hz之间的减振效果较好;隧道埋深大于11 m,以及采用减振垫轨道结构的情况下,隧道正上方地面和楼层的Z振级最大值均小于70 dB,能够满足环评标准的要求。
Damping track is a kind of track structure commonly used on higher vibration reduction in urban rail transit.To study the effect of it on environmental vibration induced by vehicle,the damping track modal is analyzed firstly.Then,a model of subway train-damping track-tunnel-soil-building system is established,which is further divided into two sub-models.The vertical wheel/rail force in sub-model 1 is taken as the external excitation of sub-model 2,the vibration acceleration characteristics and vibration level characteristics of track slab,tunnel wall,ground and floor induced by vehicle are calculated and analyzed.Research results show that in the transmission route of vibration induced by train operation,the vibration decrement of track slab to tunnel wall is much greater than that of tunnel wall to ground,while the vertical vibration acceleration level of floor and ground is basically the same;the 31.5 Hz and 80 Hz center frequencies of two peaks corresponding to the 1/3 octave acceleration level of the track plate,tunnel wall,ground and floor are related to the natural frequencies of the fifth and the tenth main modes of the track slabs;when the center frequency is between 3.15 Hz and 8 Hz,the vibration damping effect is better;when the burial depth of tunnels is deeper than 11 meters and the damping track is used to reduce the vibration,the maximum value of the vibration level Z on the ground floor above tunnel and the building is less than 70 dB,which can meet the environmental assessment criteria.
作者
臧景超
杨新文
祁正海
马晓云
ZANG Jingchao;YANG Xinwen;QI Zhenghai;MA Xiaoyun(State Key Laboratory of Road and Traffic Engineering,Tongji University,Shanghai 201804,China)
出处
《城市轨道交通研究》
北大核心
2019年第3期90-93,165,共5页
Urban Mass Transit
