地铁扣件刚度对车致轨道-隧道振动影响分析

Analysis of Influence of Rail Fastener Stiffness on Vehicle-induced Track-tunnel Vibration

为揭示减振扣件动力性能参数对轨道-隧道振动特性的影响规律,对减振扣件轨道与一般非减振轨道的动力响应进行现场实测,对比分析两种类型轨道的钢轨、道床与隧道壁的振动特性,同时建立车辆-轨道耦合动力学仿真模型与轨道-隧道-大地有限元模型,进行不同扣件刚度下钢轨加速度导纳、轨道振动衰减率与隧道动力响应的影响分析。对比线上实测结果发现,减振扣件轨道中钢轨、道床与隧道壁的振动均明显减弱;减小扣件刚度对车体的振动响应无显著影响,钢轨的位移与加速度会随之增大;减小扣件刚度会增强钢轨的低频振动,但会减弱钢轨的高频振动;沿钢轨纵向1~50Hz频段的振动耗散更为迅速,500~1000Hz频段的振动更容易沿着钢轨纵向传播;减振扣件对50~200Hz频段隧道动力响应有明显影响,能有效降低隧道壁测点处振动响应6~8dB。

In order to reveal the influence law of dynamic performance parameters of damping fasteners on the vibration characteristics of track-tunnel structures,the dynamic responses of damping fasteners track and common track are measured on site.The vibration characteristics of rail,ballast bed and tunnel wall of two types of tracks are analyzed and compared.The vehicle-track coupling dynamic simulation model and the track-tunnel-ground finite element model are established,and the effects of rail acceleration mobility,track vibration decay rate and tunnel dynamic response under different fastener stiffness condition are analyzed and compared.The results show that the vibrations of rail,track bed and tunnel wall in the damping fasteners track are obviously weakened.Reducing the fastener stiffness has no significant effect on the vibration response of the train body,but can cause the increase of the displacement and acceleration of the rail.Reducing the fastener stiffness will enhance the low-frequency vibration of the rail,but will weaken the high-frequency vibration of the rail.In the longitudinal direction of the rail,the vibration dissipation in the 1-50 Hz frequency band is more rapid,and the vibration in the 500-1000 Hz frequency band tends to transmit along the longitudinal direction of the rail.The use of damping fasteners has a significant effect on the dynamic response of the tunnel in the 50-200 Hz frequency band,which can effectively reduce the vibration response at the measurement point of the tunnel wall by 6-8 dB.