客运专线桥上纵连式无砟道岔伸缩力与位移影响因素分析

以武广客运专线雷大特大桥铺设CRTSⅡ型纵连式无砟道岔为例,将一组客专18号渡线、CRTSⅡ型板式无砟轨道、桥梁、墩台视为一个系统,建立了岔-板-梁-墩一体化计算模型,分析了道岔、道床板、桥墩的受力和变形规律,以及道床板伸缩刚度、滑动层摩擦系数、固结机构等对各部分变形的影响。分析结果表明:基本轨伸缩附加力和纵向位移随道床板纵向伸缩刚度的减少而越大,道岔传力部件受力随道床板伸缩刚度减小而明显减小;滑动层失效不会对轨道结构的变形造成较大影响,但对墩台和固结机构受力不利;大跨桥上有必要设置固结机构,取消固结机构对基本轨位移变化及桥梁墩台受力不利。

Influencing Factors of Temperature Force and Displacement of Longitudinally Coupled Ballastless Welded Turnout on Bridges of Dedicated Passenger Lines

Taking the longitudinally coupled ballastless turnout on the Leida Bridge of the Dedicated Wuhan-Guangzhou Passenger Line for instance,the integral finite element model of turnout(crossover)-track slab-bridge-pier was established,in which two No.18 welded turnouts with movable frog in the form of crossover,longitudinally coupled CRTSⅡ ballastless track,bridges and piers were regarded as one system.Laws of additional temperature forces and deformation of turnouts,track slab,bridges and piers were analyzed on the basis the model.Besides,parameters of influence on different Parts of deformation were researched,such as the expansion stiffness of track slab,friction coefficient of the slip layer and fixing of the anchor point.Calculation results show as follows: additional longitudinal forces and displacement of stock rails due to temperature changes increase with the reduction of longitudinal slab expansion stiffness,whereas the forces of transmission components of turnonts such as position-limited devices and spacer blocks,decrease remarkably with the reduction of longitudinal slab expansion stiffness.The friction coefficient of the slip layer has no great influence on longitudinal distortions of the track structure,but it is unfavorable for stressed characteristics of piers and fixings.It is necessary to arrange anchor points on large-span bridges because their cancellation may affect stock rail displacements and pier stressing adversely.