简支梁桥上有轨电车嵌入式轨道纵向力分析

摘要

研究目的:因桥上无缝线路梁轨相互作用较为复杂,桥梁和轨道结构的受力与变形特性成为国内外学者的热点研究问题.为研究温度荷载、列车荷载和制动荷载作用下轨道结构的受力与变形规律及影响因素,根据嵌入式轨道的特点,本文通过建立嵌入式轨道桥上无缝线路有限元模型,计算伸缩力、挠曲力和制动力三种工况下轨道结构的受力与变形情况,并分析梁体温差、高分子材料纵向阻力和墩台纵向刚度对伸缩力的影响.研究结论:(1)嵌入式轨道的线路纵向阻力和垂向刚度均为线性变化,且轨板相对位移限值为6.2 mm;(2)轨道结构的受力和变形均随着梁体温差的增加而线性增加,允许梁体温差为38℃;随着线路纵向阻力的增加,钢轨纵向位移和伸缩力逐渐增大,而轨板相对位移则逐渐减小;桥梁墩台纵向刚度对轨道结构的受力和变形影响较小;(3)在挠曲力和制动力工况下,轨板相对位移和钢轨附加力均较小,故在设计时应重点关注伸缩力工况;(4)当梁体温差和轨温变化幅度为30℃时,钢轨强度和轨板相对位移均满足要求,因此在32 m简支梁上铺设有轨电车嵌入式轨道无缝线路是可行的;(5)本研究成果对桥上有轨电车嵌入式轨道设计具有参考价值.%Research purposes:The interaction between rail and beam of CWR on bridge is really complex,and the stress and deformation characteristics of bridge and track structure become a hot research topic of scholars at home and abroad.In order to study the force and deformation and influence factors of track structure under temperature load,train load and braking load,according to the characteristics of the embedded track,the finite element model of embedded track CWR on bridge is established,the force and deformation of the track structure under three conditions are calculated,such as expansion-constriction force,deflection force and braking force,the influence of beam temperature difference,the longitudinal resistance of polymer material and the longitudinal stiffness of the pier on the expansion-constriction force is analyzed.Research conclusions:(1) The longitudinal resistance and vertical stiffness of the embedded track are linear,and the relative displacement limit between rail and substructure is determined to be 6.2 mm.(2) The force and deformation of track structure increase linearly with the increase of beam temperature difference,and the allowable beam temperature difference is 38 ℃;With the increase of the longitudinal resistance of the track,the longitudinal displacement and the expansion-constriction force of the rail increase gradually,while the relative displacement between rail and substructure decreases gradually;The longitudinal stiffness of the bridge piers has little effect on the force and deformation of the track structure.(3) Under the condition of deflection force and braking force,the relative displacement between rail and substructure and the additional force of rail are small,so the expansion-constriction force condition should be paid attention to in the design.(4) When the beam temperature difference and the change of the rail temperature is 30 ℃,the strength of rail and the relative displacement between rail and substructure meet the requirements.Therefore,it is feasible to lay the embedded track on 32 m simply supported beam.(5) The research results have reference value for the design of tram embedded track on bridge.