考虑CA砂浆层随机损伤的CRTSⅡ板式无砟轨道-连续箱梁桥结构受力性能演化研究

In China the high speed railway is expending rapidly, where lots of continuous box beam bridges are working and suffering vehicle load, temperature in all the service life. The damages of the CA motar (cement emulsified asphalt mortar), who connect the track plate and base plane, are becoming more common and serious presently in part of lines. The theoretical and experimental studies for influence to the cooperative working performance, the evolution of the service performance, are in urgent need. In this subject, firstly the experiments for the vertical, tangential, and complicated mechanical properties will be tested, and the mechanical property development and CA mortar stochastic damage constitutive relation will be presented. Secondly, the multi-scales FEM model for the ballastless track-continuous box beam will be setup, with the concrete and CA mortar stochastic damage constitutive relations. The whole structural system analysis will be followed for the cooperative working performance and evolution under material damage, vehicle load, temperature. Thirdly a practical design method for the cooperative working performance and stochastic damage will be presented. The achievement in this subject will improve the research and maintenance technology for bridges in high speed railway, present theoretical basis and Technical support for design theory and technology system with China's independent intellectual property rights.

我国高速铁路迅速发展，大量连续箱梁桥结构投入使用并经受列车荷载、温度作用的长期连续损伤。CA砂浆填充层（水泥乳化沥青砂浆层）连接轨道板和底座板并部分出现病害，亟待开展其对无砟轨道-连续箱梁桥结构体系协同工作受力性能影响的理论和试验研究。本课题首先开展CA砂浆法向、切向和复杂条件下力学性能试验，探讨CA砂浆材料在列车荷载、温度作用下的性能发展规律和随机损伤本构关系；然后建立该结构体系多尺度数值模型，引入CA砂浆和混凝土随机损伤本构关系，研究整个结构体系在材料损伤、列车荷载、温度作用下长期协同工作性能和受力性能演化规律；最后提出考虑协同工作和材料随机损伤的高速铁路无砟轨道-连续箱梁桥结构体系实用设计方法。研究成果将进一步提升我国高速铁路无砟轨道-桥梁结构研究水平和养护技术，为形成具有我国自主知识产权的无砟轨道体系提供理论依据和技术支撑。

本课题首先建立该结构体系精细化多尺度数值模型，引入CA砂浆和混凝土随机损伤本构关系，研究整个结构体系在材料损伤、列车荷载、温度作用下长期协同工作性能和受力性能演化规律；制作了无砟轨道-桥梁结构试验模型，通过开展快速升降温试验，分析了CRTSⅡ型无砟轨道二维温度场分布规律，提出了轨道系统横、竖向温度三维分布型式；开展了重复温度荷载试验，研究了重复温度荷载作用对无砟轨道-简支梁桥结构体系应变、位移的影响以及层间离缝的发展规律。研究了结构体系混凝土材料共同失效和各层材料共同失效时桥梁-轨道结构的协同工作机理，重点探讨了CA砂浆层疲劳劣化与否对结构体系受力变形的影响，揭示了结构体系性能演化动态进程。研究成果将进一步提升我国高速铁路无砟轨道-桥梁结构研究水平和养护技术，为形成具有我国自主知识产权的无砟轨道体系提供理论依据和技术支撑。