地铁线路隧道沉降对车辆-轨道系统力学特性的影响

Influence of tunnel settlement on mechanical properties of metro vehicle-track system

为评估地铁线路隧道沉降对车辆-轨道系统力学特性的影响,基于有限元(FE)方法和车辆-轨道耦合动力学理论,建立地铁车辆-轨道-下部基础动力学耦合模型,并以北京某地铁线路为例,分析沉降作用下系统的静、动力学特性。研究结果表明:上部不平顺幅值与沉降幅值基本呈1∶1传递;在沉降区边界道床有拉裂的风险;车辆进入沉降区域后,轮轨垂向力因下凹曲线变化率影响出现冲击-减载-平稳-冲击现象;随着沉降量的增加,车辆动力学指标基本呈线性增长,沉降幅值从5 mm增长至20 mm,车体加速度峰值由0. 167 m/s^2增加至0. 259 m/s^2,增加了55. 08%。

In order to evaluate the influence of tunnel settlement on the mechanical properties of vehicletrack system,a vehicle-track-foundation dynamic coupling model was established based on the finite element(FE)method and vehicle-track coupling dynamic theory.A metro line in Beijing was taken as an example.The static and dynamic characteristics of the whole system under settlements were analyzed.The calculation results show that the upper irregularity amplitude is basically same with the settlement amplitude.There is a risk of tensile fracture for track bed at the border of settlement area.When the vehicle got into the settlement area,the vertical wheel-rail force appeared an impact-load reduction-steady-impact phenomenon due to the 1 st derivative characteristic of settlement curve.With the increase of settlement,the vehicle dynamic index increases linearly.Whenthe settlement amplitude increases from 5 mm to 20 mm,the peak value of car body acceleration will increase from 0.167 m/s^2 to 0.259 m/s^2,which increases 50%.