列车荷载与温度耦合作用下高速铁路桥上CRTSⅢ型板式无砟轨道结构疲劳损伤行为研究

高速铁路运营实践表明，在列车荷载和环境耦合重复作用下高速铁路无砟轨道结构会发生损伤劣化现象，长时间累积损伤势必将影响线路状态与列车运营品质，甚至危及行车安全。由于我国自主研发的CRTSⅢ型板式无砟轨道结构研究和运用的时间还比较短，目前尚缺乏系统深入的基础理论研究，已有的研究也并未充分考虑列车荷载与温度耦合作用的影响。为此，本项目拟通过理论分析和数值模拟研究列车荷载作用下桥上CRTSⅢ型板式无砟轨道结构疲劳损伤演化机理、长期温度作用下CRTSⅢ型板式无砟轨结构疲劳损伤特性以及列车荷载与温度耦合作用机制，发展耦合作用下桥上CRTSⅢ型板式无砟轨道结构疲劳损伤演化数值模拟方法，通过数值仿真和试验研究，揭示列车荷载与温度耦合作用下CRTSⅢ型板式无砟轨道结构疲劳损伤行为，建立耦合作用下CRTSⅢ型板式无砟轨道结构疲劳性能计算分析方法。研究成果将为板式无砟轨道结构的设计、评估和养护维修提供科学依据。

The operation practice of high-speed railway at home and abroad shows that the ballastless track structure is deteriorated due to the repeat coupled effect of train load and environmental action. The long-time accumulated damage of ballastless track structure is bound to affect the service state of high-speed railway and operation quality of high-speed train, and even endangers traffic safety. Since application and research time on the new self-developed CRTSⅢ slab ballastless track structure is relatively short, there is still lack of systematic and in-depth fundamental theory research in our country high-speed railway and the coupled effect of train load and temperature action on structural performance deterioration is not taken into account completely in the literatures. Based on theoretical analysis and numberical simulation, fatigue damage evolution mechanism of the bridge CRTSⅢ slab ballastless track structure under high-speed train load, fatigue damage behavior of ballastless track structure under long-time temperature action, and the coupled mechanism of train load and temperature action are systematically investigated. The numberical method of fatigue damage evolution for bridge CRTSⅢ slab ballastless track structure under the coupling effects is presented. The fatigue damage behavior of CRTSⅢ slab ballastless track structure under the coupling effect of fatigue loading and temperature action will be revealed by numberical simulation and experimental method. The calculation analysis method of fatigue behavior for CRTSⅢ slab ballastless track structure is established. The results will provide important science basis for design, evaluation and maintenance of slab ballastless track structure.