高速铁路桥上无砟轨道减振层刚度的动力学影响分析

摘要

In order to reduce the vibration and noise level of high-speed railway bridge and ballastless track structure, a vibration analysis model of the high-speed railway vehicle, slab track and bridge coupling system was built, which referred to Chinese CRH 2, the 32 m box girder and the CRTS I slab track as objects. Then, the dynamic effects of damping layer stiffness on the vehicle-track-bridge coupling system were comparatively analyzed considering various running speed conditions. This research could provide some helpful conclusions for the dynamical parameter design of slab track on the high-speed railway girder. Numerical results showed that the damping layer between the slab track and the girder could significantly reduce the vertical vibration acceleration of the slab track, the maximum acceleration amplitude decreased by more than 57% than that of slab track without damping layer under the calculation conditions in this paper. The slab track with damping layer could reduce the wheel-rail dynamic force slightly, and decreased the vertical vibration acceleration of the box girder by about 20%. The low-stiffness damping layer increased the vertical vibration displacement of track plate, and it would affect the running safety of the high-speed train, while the high-stiffness damping layer could not effectively reduce the vibration of the slab track. Consequently, the proposed stiffness of the low-vibration slab track on the girder was preferably in 100~200 MN/m3 based on the overall consideration.%为了降低高速铁路桥上结构的振动与噪声水平，以我国CRH2型高速车辆和32m跨度高速铁路简支箱梁及CRTS I型板式无砟轨道为对象，建立高速车辆-无砟轨道-桥梁耦合振动分析模型，分析比较了不同行车速度下无砟轨道减振层刚度对车轨桥系统动力响应的影响，为桥上减振型板式轨道动力学参数设计提供参考。计算结果表明，桥上采用减振型板式轨道可显著降低轨道板垂向振动加速度，在本文计算条件下其最大加速度幅值较无减振层时减小了57%以上；减振型板式轨道能稍微降低轮轨动力作用，可减小简支箱梁垂向振动加速度20%左右；较低的减振层刚度增大了轨道板垂向振动位移，不利于高速行车安全，而过大的减振层刚度不能有效降低轨道结构振动，综合考虑后建议桥上减振型板式轨道弹性垫层刚度在100～200 MN/m3之间选取。