【作者】 陈卓；

【导师】 于向东； 刘胤虎；

【作者基本信息】 中南大学 ， 土木水利（专业学位）， 2023， 硕士

【摘要】 有砟轨道桥上无缝线路的梁轨相互作用问题是高速铁路桥梁设计与检算过程中的重要内容,在计算中小跨度桥梁梁轨系统纵向附加力过程中常忽略活动支座摩阻力的影响,而大跨度铁路桥梁的活动支座摩阻力远大于中小跨度桥梁以致于其影响并不能完全忽略。鉴于此,本文以国内首座高速铁路大跨度悬索桥——五峰山长江大桥为研究对象,采用ANSYS有限元分析软件建立了可以考虑活动支座摩阻效应的悬索桥桥梁-轨道-塔墩空间有限元分析模型,研究支座摩阻效应对悬索桥梁轨相互作用的影响,探讨了计入支座摩阻力后缆索温度变化、梁端布置钢轨伸缩调节器前后及不同制动力率等因素的影响,对计入支座摩阻力后多荷载耦合作用下的梁轨相互作用进行了对比分析,本文主要研究内容和工作成果如下:(1)对国内外梁轨相互作用的相关理论研究进行了归纳总结,基于梁轨相互作用原理和有限元理论建立了悬索桥空间一体化有限元模型,该模型采用双线性恢复力模型模拟活动支座的摩阻效应。通过与设计文件对比验证了模型计算结果的准确性与可靠性,以用于后续悬索桥上钢轨附加力的计算。(2)基于上述模型,分析了不同支座摩阻系数下悬索桥上各钢轨纵向力的分布规律,结果表明活动支座摩阻力对大跨度悬索桥的制动附加力、偏载下的挠曲附加力和断轨附加力的影响比较显著,对伸缩附加力和对称加载下的挠曲附加力的影响较小;计入活动支座摩擦力后,钢轨的制动附加力、偏载下的挠曲附加力迅速减小,活动墩墩顶水平力显著增大,随着摩阻系数的增大,钢轨制动附加力、偏载下的挠曲附加力和断轨后钢轨断缝宽度呈不断减小趋势,而主塔和活动墩的墩顶水平力则呈不断增大趋势。(3)列车荷载加载位置对不同活动支座摩阻力下的挠曲附加力的分布规律影响很大,对制动附加力的分布规律影响相对较小;缆索温度变化对跨中拉应力影响显著,考虑缆索升温后的跨中最大钢轨附加拉应力比不考虑时增大了约30%;梁端布置钢轨伸缩调节器后,不同支座摩阻系数下两侧梁端的伸缩力、挠曲力、制动力以及固定墩的墩顶水平力与布置前相比大大降低,而活动墩的墩顶水平力与布置前相比却变化很小;计入支座摩阻力后,制动力率从0.1到0.164、0.25及0.32,南侧梁端的最大压应力分别增大了1.67倍、2.49倍和3.13倍,合理的选取制动力率对计算钢轨制动力十分关键。(4)对于耦合计算,温度与挠曲耦合以及温度、挠曲和制动的多荷载耦合作用下线性叠加计算的钢轨应力与考虑加载历程的计算结果相比更偏于保守,其中温度与挠曲耦合工况下线性叠加计算的钢轨应力在不同支座摩阻系数下比考虑加载历程时偏大了25%～14%,温度、挠曲和制动耦合工况下线性叠加比考虑加载历程偏大了27%～16%,且随着支座摩阻系数的增大,两者的差距随之减小;而挠曲与制动荷载耦合作用下两种计算方式的结果却差距很小。图69幅,表20个,参考文献108篇更多还原

【Abstract】 The track-bridge interaction of the continuous welded rails on ballasted track bridges is an important content in the design and calculation of high-speed railway bridges.The influence of bearing friction is often ignored in the calculation of the longitudinal additional force of the track-bridge system of small and medium span bridges,while the bearing friction of long-span railway bridges is much larger than that of small and medium span bridges so that its influence cannot be completely ignored.In view of this,this thesis takes the China’s first high-speed railway long-span suspension bridge as the research object.ANSYS finite element analysis software is used to establish a bridgetrack-tower-pier spatial finite element analysis model of the suspension bridge that can take into account the influence of bearing friction.The effect of bearing friction on the girder-rail interaction of suspension bridge is studied,and the effects of cable temperature change,before and after the arrangement of rail expansion regulator at the girder end and different braking force rates after taking into account the bearing friction are discussed.The influence of bearing friction on track-bridge interaction of the suspension bridge is studied.The influence of the cable temperature change,the arrangement of rail expansion adjuster at the end of the beam and the different braking force rate after taking into account the bearing friction are discussed.And the track-bridge interaction under complex operating conditions after taking into account the bearing friction are compared and analyzed.The main research contents and results of this thesis are as follows:(1)The relevant theoretical studies on track-bridge interaction at home and abroad are summarized,and a spatially integrated finite element model of suspension bridge is established based on the principle of track-bridge interaction and finite element theory,which uses a bilinear restoring force model to simulate the frictional effect of movable bearings.The accuracy and reliability of the model calculation results were verified by comparing with the design documents for the subsequent calculation of the additional force of the rails on the suspension bridge.(2)Based on the model,the distribution law of longitudinal forces of rails on suspension bridges with different bearing friction coefficients is analyzed,and the results show that the influence of bearing friction on the braking additional forces,flexural additional forces under eccentric load and rail-broken additional forces of long-span suspension bridges is relatively significant,and the influence on expansion additional force and flexural additional forces under symmetrical load is smaller.After taking into account the movable bearing friction,the braking additional force of rails and flexural additional forces under eccentric load are decreasing rapidly,the horizontal force on the top of movable piers are increasing significantly.With the increase of friction coefficient,braking additional forces,flexural additional forces under eccentric load and the rail-broken gap decrease,while the horizontal force on the top of main tower’s piers and movable piers increase.(3)Train load loading position on the distribution law of flexural additional forces under different bearing friction resistance have great influence,the distribution law of braking additional forces have relatively small influence;cable temperature changes on the mid-span of tensile stress is significant,the maximum additional tensile stress of the rail in the span after considering the cable warming is about 30% higher than when it is not considered;after the arrangement of rail expansion adjuster at the beam end,the expansion additional force,flexural additional force and braking additional force at both sides of the beam end under different bearing friction coefficients are greatly reduced compared to those before arrangement,and the horizontal force at the top of the fixed piers are also reduced,while the horizontal forces at the top of the movable piers are almost unchanged compared to those before arrangement;after taking into account the influence of bearing friction,the braking force rate increases from 0.1 to 0.164,0.25 and 0.32,and the maximum compressive stress at the southern beam end increases by 1.67,2.49 and 3.13 times respectively,reasonable selection of braking force rate is very critical to calculate the rail braking additional force.(4)For coupling calculations,the rail stresses calculated by linear superposition under temperature-flexure coupling and temperatureflexure-brake coupling are more conservative compared with the calculation results considering the loading history,in which the rail stresses calculated by linear superposition under temperature-flexure coupling are 25%～14% larger than considering the loading history under different bearing friction coefficients,the rail stresses calculated by linear superposition under temperature-flexure-brake coupling are 27%～16%larger than considering the loading history under different bearing friction coefficients,and the difference between the two decreases as the bearing friction coefficient increases;while the results of the two calculation methods under flexure-brake coupling are very different.更多还原