中文摘要：

研究目的：既有桥上纵连板式无砟轨道研究多考虑桥梁整体温度变化而忽略温度梯度的影响，为探明高速铁路大跨度桥上纵连板式无砟轨道系统受力规律，本文基于长期实测温度场数据，利用统计方法获得结构具有概率保证的非线性温度模式，建立考虑钢轨-轨道板-底座板-梁体-桥墩的空间一体化有限元模型，选取沪昆客运专线某大跨连续梁桥工程实例，计算分析实测非线性温度模式下桥上各层轨道结构相对位移以及钢轨纵向附加力的分布规律。研究结论：（1）只考虑轨道板及底座板实测温度模式时，钢轨附加应力基本为0；（2）桥梁温度梯度会引起梁缝处钢轨附加应力的急剧增大，在研究桥上纵连板式无砟轨道时需考虑桥梁温度梯度的影响；（3）大跨度连续梁桥固结机构处水泥沥青砂浆变形会超过其实测极限变形位移，建议在连续梁固结机构上方同样设置剪力钢筋；（4）无砟轨道断板会导致钢轨附加应力急剧增大，因此应严格限制纵连板式无砟轨道断裂的发生，若需更换轨道板及底座板时，应在合龙温度范围进行更换；（5）本研究结果可为大跨度桥上纵连板式无砟轨道的设计与改进提供参考。

英文摘要：

Research purposes： As , Hunan 410075, China） the existing researches on the longitudinally connected ballastless track mostly consider the variation of the overall temperature of the bridge and neglect the structural temperature gradient, a non - linear structural temperature pattern is fitted through statistical methods on the basis of the temperature field data, the data is acquired through the long term measurement on the field. A finite element model which considers the integration of rail, track plate, base plate, bridge and pier is established. A practical example of a certain large - span continuous girder bridge of Shanghai - Kunming high - speed railway is selected in this paper. The relative displacements between the various layers of track structures and the distribution rules of the longitudinal additional stress of the rail are respectively analyzed under the nonlinear temperature mode. Research conclusions： （ 1 ） The rail additional stress is nearly 0, when only consider the temperature pattern of track plate and bed plate. （2） The temperature gradient of the bridge will trigger the sharp increase in the rail additional stress of the beam crevice, the structural temperature gradient needs to be considered in the research on longitudinally connected ballastless track. （3） The deformation of cement and asphalt mortar above the consolidation of the large -span continuous bridge exceeds its ultimate deformation tested by the experiment, it is suggested that shear reinforcement should also be installed above the consolidation of the continuous girder bridge. （4） Broken plate will cause the significant increase of the rail additional stress, and therefore, the occurrence of the fracture of the longitudinally connected ballastless track should be rigorously restricted, and the exchange of the ballastless track should be done within the closure temperature. （ 5 ）The research results can provide reference for the design and improvement of longitudinal slab ballastless track on long