高架钢弹簧浮置板轨道减振特性研究及参数优化

Vibration Reduction Study and Parameter Optimization of Steel Spring Floating Slab Tracks in Metro Viaducts

为探讨钢弹簧刚度和浮置板密度对高架钢弹簧浮置板轨道减振特性的影响规律,构建车辆-浮置板轨道-桥梁耦合模型,从时频域的角度对其进行分析,为钢弹簧浮置板轨道的设计参数的合理选择与组合优化提供理论依据。研究结果表明:在2 Hz^20 Hz范围内浮置板的振动水平随钢弹簧刚度的减小而增大。在16 Hz^125 Hz频率范围内,轨道中心线、翼缘、腹板、梁底的振动水平随着钢弹簧刚度的减小而减小,最大减幅达到13 dB。钢弹簧刚度的变化对传递函数的影响比较明显,弹簧刚度越小,浮置板到桥梁结构的竖向传递函数值越小。综合考虑,在设计浮置板轨道结构时建议将钢弹簧的刚度控制在6×106N/m^8×106N/m。浮置板密度的增大会在一定程度上减小系统的振动水平,实际设计中要合理设置浮置板密度,建议控制在2 800 kg/m3~3 200 kg/m3。

To inquire the influence of the steel spring stiffness and density of the floating slab on the vibration damping characteristics of elevated steel spring floating slab tracks,the vehicle-train-bridge coupling model of a floating slab track(FST)is built and analyzed in time and frequency domains.The results show that the vibration level of the floating plate increases with the decrease of the steel spring stiffness in the frequency range of 2 Hz-20 Hz.In the frequency range of 16 Hz-125 Hz,the vibration level at the centerline,the flange,the web and the beam bottom of the track decreases with the decrease of the stiffness of the steel spring,and the maximum value of the vibration level is reduced to 13 dB.The stiffness of the steel spring has an obvious effect on the transfer function.The value of the vertical transfer function from the floating plate to the bridge structure decreases with the decreasing of the stiffness of the steel spring.Considering the influence of the steel spring stiffness change on bridge structure vibration level and the transfer function value,it is suggested in the design of FST structures that the steel spring stiffness should be within 6×106 N/m-8×106 N/m.The increase of the floating plate density will reduce the vibration level of the system.In actual design,the floating plate density should be in the range of 2 800 kg/m3-3 200 kg/m3.These results may provide a theoretical basis for the reasonable selection and optimization of the steel spring FST parameters.