高速铁路大跨度桥梁与无缝线路相互作用机理及适应性

For long-span bridges in high-speed railway, the expansion length and the deck-end rotation are relatively large, and the track-bridge interaction is a quite significant dominant factor for the design and safe operation of the long-span bridges and continuous welded rails. However, most of the existing specifications and criteria at home and abroad are mainly focused on the small and medium bridges and not appropriate for all long-span bridges yet. Based on the nonlinear spatial analysis theory of track-structure system of long-span bridges, main topics will be carried out in this project as follows: (1) By establishing the track-bridge nonlinear analysis model which takes the influence of the load history into account, the track-bridge interaction under the effect of multi-field coupling will be researched. (2) Considering the shielding effect of the track system and the regional conditions, the solar temperature field will be simulated, and the spatial temperature calculation model of long-span bridges will be proposed in this project. (3) The applicability of various track types and long-span bridges in high-speed railway will be investigated, the arrangement condition and method of rail expansion devices will be studied, and the feasibility of paving ballastless track on long-span bridges will be explored. (4) The controlling conditions of design parameters of continuous welded rail on long-span bridges, such as the expansion length, rail stress, track-beam relative displacement as well as the displacement of pier top will be researched and proposed. A series of theory and experimental studies will be undertaken and the conclusions from this work can be used to form the basis of a design specification on the track-bridge interaction of long-span bridges in high-speed railway.

高速铁路大跨度桥梁温度跨度大，活载作用下梁端转角大，轨道与桥梁相互作用是大跨度桥梁与无缝线路设计及安全使用的重要控制因素，而现有的国内外规范及标准多针对中小跨度桥梁，并不完全适用于大跨度桥梁上的无缝线路。本项目基于大跨度桥梁与轨道结构的非线性空间分析理论，开展以下研究：（1）建立考虑加载历史的梁轨一体化空间非线性分析模型，研究多场耦合作用下大跨度桥梁与轨道相互作用机理；（2）研究考虑轨道结构及地域条件的梁轨系统日照温度场，提出大跨度桥梁及轨道的空间温度计算模式；（3）研究无砟轨道和有砟轨道与高速铁路大跨度桥梁的适应性及钢轨伸缩调节器的设置方法，探索无砟轨道在大跨度钢桥上铺设的可行性；（4）提出大跨度桥梁温度跨度、钢轨应力、梁轨相对位移、墩顶位移等桥上无缝线路设计参数的控制条件。 通过对上述问题的理论和试验研究，可为完善我国大跨度桥梁与轨道相互作用设计与检算标准提供依据。

高速铁路大跨度桥梁温度跨度大，活载作用下梁端转角大，轨道与桥梁相互作用是大跨度桥梁与无缝线路设计及安全使用的重要控制因素，而现有的国内外规范及标准多针对中小跨度桥梁，并不完全适用于大跨度桥梁上的无缝线路。本项目采用理论分析、数值仿真与现场试验相结合，针对高速铁路大跨度桥梁与无缝线路相互作用的机理及适应性开展研究。基于大跨度桥梁与轨道结构的非线性空间分析理论，提出阻力差值法实现无载、有载线路阻力的转换，计入加载历史对梁轨非保守系统的影响。开展温度场现场实测，通过海量数据的统计分析，提出轨道、箱梁和箱梁-轨道结构的均匀温度曲线方程；通过热力学数值仿真与温度场试验测试结果进行对比验证，明确了轨道结构遮挡效应对桥梁-轨道系统温度场的影响，分别提出了考虑轨道遮挡效应前后桥梁-轨道系统的温度荷载计算模式。建立了高速铁路典型桥梁-轨道一体化分析模型，探明了不同轨道类型与高速铁路大跨度桥梁的适应性。提出具有普遍适用性的桥上无缝线路钢轨在温度作用下的伸缩力解析算法，为桥上无缝线路的桥梁温度跨度及线路纵向阻力的选择提供依据。通过上述理论和试验研究，研究成果可为完善我国大跨度桥梁与轨道相互作用设计与检算标准提供依据。