高速铁路斜拉桥上无缝线路动态变形机制及长期服役性能研究

Continuously welded rail track is the inevitable choice and the core technology of high-speed railway. There is a large proportion of high-speed railway bridges in China. Followed by the traditional concrete bridge and steel bridge, long span cable-stayed bridge is gradually appearing. Cable-stayed bridge is more sensitive to temperature and train load. Besides adapting to complex climate, continuously welded rail track on bridge should also be in harmony with the large deformation of the beam body. At present, the related researches are fewer on continuously welded rail track of cable-stayed bridge. Especially, there are lack of researches on the interaction between structure, mechanical behavior, state evolution, dynamic influence and so on relatively. A series of problems related to dynamic stability and continuously welded rail track service state, which the complex deformation of cable-stayed bridge leads to, are to be solved..The project considers the interaction between the multi-layer heterogeneous structure of the continuously welded rail track on cable-stayed bridge. And macroscopic and mesoscopic coupling model will be set up, revealing the mechanical behavior of the continuously welded rail track on cable-stayed bridge. Based on time-varying model and field data, the service behavior and the law of state evolution of continuously welded rail track on cable-stayed bridge will be proposed. Based on collaborative simulation method, dynamic model will be established to investigate the influence of line state on vehicle-rail-bridge system. Comprehensive consideration of factors such as strength, regularity, stability, suggestions on design optimization, reasonable quality evaluation methods and safeguard measures of continuously welded rail track on cable -stayed bridge will be proposed. Through this project research, design theory and maintenance technology of China high-speed railway continuously welded rail track will be supplied and perfected.

无缝线路是高速铁路的必然选择和核心技术。我国高铁桥梁比例大，继传统混凝土桥和钢桥等之后，大跨斜拉桥也逐渐出现。斜拉桥对温度、列车荷载更为敏感，桥上无缝线路除与复杂气候相适应外，还需与梁体空间大变形相协调。目前，针对斜拉桥上无缝线路的相关研究较少，特别是结构间相互作用、力学行为与状态演变、动力影响等研究相对匮乏。斜拉桥复杂变形导致的一系列与无缝线路动态稳定性、服役状态相关的问题亟待解决。.项目考虑无缝线路-斜拉桥多层异质结构间的相互作用，建立细观与宏观结合的空间耦合模型，揭示斜拉桥无缝线路力学行为。基于时变模型和现场数据，提出桥上无缝线路的服役行为与状态演变规律。基于协同仿真方法建立动力学模型，研究线路状态对车-轨-桥系统的影响，综合考虑强度、平顺性、稳定性等因素，提出斜拉桥上无缝线路设计优化建议、质量评估方法与合理维护措施。通过本项目研究，补充完善我国高速铁路无缝线路设计理论与维护技术。

斜拉桥是跨度最大、结构最为复杂的桥型之一，近年来在我国高铁上逐步推广应用。针对高速运营、长期荷载对无缝线路-斜拉桥相互作用机制的影响，项目重点研究了无缝线路-道床-斜拉桥间相互作用关系、桥上无缝线路受力变形特征及影响因素、复杂运营下桥上无缝线路长期服役性能、无缝线路状态对车-轨-桥系统动力学行为的影响、桥上轨道系统设计优化及动态稳定性控制5个方面的内容。主要创新工作与成果如下：.1）建立了无缝线路-有砟道床-斜拉桥空间耦合精细化模型。采用双层非线性弹簧模拟钢轨、轨枕与梁体的相互作用，形成塔-索-梁-枕-轨耦合作用体系。斜拉桥的一阶模态为纵飘+反对称竖弯。.2）揭示了复杂温度组合、列车、偶然荷载下桥上无缝线路的变形传递机制与力学特性分布规律。斜拉桥梁端无缝线路受力变形最为不利，在复杂荷载下将产生较大的位移和附加力，梁端需设置调节器。.3）提出了考虑加载历史的线路纵向阻力滞回本构及连续荷载步的瞬态分析方法。线路阻力超过弹塑性临界点时，卸载后钢轨中仍存在纵向力。无缝线路施工锁定至开通运营期间，在日温度变化下，线路阻力将呈现滞回现象。.4）建立了车-轨-斜拉桥耦合动力分析模型。基于离散傅立叶变换法，生成时序不平顺序列作为轮轨系统的激励。列车经过调节器尖轨时振动加速度、轮轨垂向力与横向力显著增加。轨道与桥梁的变形具有很强相关性，越靠近支座，轨道变形越小。.5）提出了静、动态相结合的桥上无缝线路优化设计方法。斜拉桥梁端应采用大量程调节器+抬枕装置。对调节器伸缩量的影响从大到小依次为温度、地震、断轨、挠曲荷载、制（启）动荷载。无缝线路动态稳定性主要受道床阻力、弹性初弯和梁体温度变形影响。.成果指导了10余座高铁大跨桥上无缝线路设计与运维。项目共发表文章38篇，其中SCI论文12篇、EI论文19篇。主持人入选教育部青年长江学者，培养硕士生9人、博士生3人，协助团队培养博士生2名。授权专利5项，获得相关奖励近10项。