高速铁路桥上有砟-无砟轨道过渡段动力学研究

Dynamic analysis of ballasted-ballastiless track transition section on high speed railway bridge

基于京沪高速铁路特大桥上的有砟轨道与CRTS II型板式无砟轨道之间的过渡段实例,建立车辆-轨道耦合动力学有限元计算模型,通过不同结构处理措施对有砟-无砟轨道过渡段动力学特性的影响研究,研究表明：当有砟轨道轨下胶垫刚度为55～75 MN/m,无砟轨道轨下胶垫刚度为20～30 MN/m时,有砟轨道的整体刚度大于无砟轨道;当有砟轨道轨下胶垫刚度为55～75 MN/m,无砟轨道轨下胶垫刚度为40～50 MN/m时,无砟轨道整体刚度与有砟轨道大体相当;过渡段枕、宽枕等不宜在有砟轨道刚度大于无砟轨道时使用;采用道砟胶结后提高了道床的整体性及过渡段轨道结构的稳定性,但增加了轨道刚度,应同时降低轨下胶垫刚度,以减小轮轨力;辅助轨只是增加了轨道结构的稳定性,对轨道刚度影响较小。

Based on the living example of transition section between ballasted track and CRTS Ⅱ ballastless track on the super large bridge of Beijing-Shanghai high-speed railway,a finite element vehicle-track coupling model was established,and the influences of different structural measures on dynamic characteristics of the transition section were studied. The results show that the overall stiffness of the ballasted track is greater than that of ballastless track when the under-rail pads stiffness of ballasted track is 55 ～75 MN / m and that of ballastless track is 20 ～30 MN / m. The overall stiffness of ballasted and ballastless track are roughly identical when the rail pad stiffness of ballasted track is 55 ～75MN / m while that of ballastless track is 40 ～50 MN / m. Transition sleeper and wide sleeper are unsuitable to be used in the transition section when the ballasted track stiffness is greater than that of ballastless track. The ballast glue improves the integrity of ballast bed and the stability of track structure in transition section but it also increases the track stiffness.In order to reduce the wheel-rail forces caused by the increased track stiffness,the rail pad stiffness has to be decreased.The auxiliary rails enhance the stability of track structure but it has little impact on the track stiffness.