摘要:研究目的:CRTS !型板式无砟轨道是我国高速铁路的主要轨道结构形式，但目前对其疲劳性能的研究 仍较少。为研究温度与列车荷载耦合作用下CRTS Ⅰ型板式无砟轨道的疲劳性能，依据无砟轨道结构实际受 荷特点，同时对先张及后张Ⅰ型板进行500万次原型疲劳试验，试验中分析轨道结构各部件位移及轨道板应 力随环境温度及列车荷载疲劳作用次数的变化，同时监测轨道板板底脱空高度的变化。 研究结论：(1)环境温度会在一定程度上影响钢轨垂向位移，对轨道板板端、轨道板1/4板端、底座板板 端垂向位移及轨道板纵向应力影响较为明显;（2)随着疲劳作用次数的增加，轨道板垂向位移、底座板垂向位 移及轨道板应力均有不同程度的减小；（3)当疲劳作用次数小于62. 5万次时，轨道板平均脱空高度变化较 小，当疲劳作用次数大于62.5万次时，随着疲劳次数的不断增加，轨道板脱空显著增加；（4)先张CRTS Ⅰ型 轨道结构的轨道板垂向位移、轨道板应力及轨道板脱空受温度及列车荷载的影响更为明显；（5)本研究成果 可为CRTS Ⅰ型板式无砟轨道的设计和维修提供一定的试验依据。

Abstract:Research purposes: CRTS III slab track is one of the main non - ballasted track type used in Chinese high speed railways. But at present，a little research has been devoted to the analysis of tlieir fatigue behavior. In order to research the fatigue characteristic of CRTS III slab track under temperature and train load，based on the load character of slab track，the 5 million cycle fatigue prototype test of CRTS III slab track witli pre - tensioning and post - tensioning prestressed slab was simultaneously conducted in this paper. The deformation of track components and the stress of slab was tested under the environmental temperature and cyclic train loading， at the same time，the change of cavity height beneath the track slab with the increased cyclic numberwas monitored in this experiment. Research conclusions ：( 1) The environment temperature has some influence on the vertical deformation of rail，while it has a significant influence on the vertical deformation at the end of slab，at a distance of 1/4 slab length from the end of slab，at the end of roadbed and the stress of slab. (2) With the increase of cyclic number of train loading，the stress of track slab，the vertical deformation of slab and roadbed both decrease in different degree. (3) The height of the cavity beneath the track slab changes slightly when the train load cycle number is less than 625 000，then it will distinctively increase witli the increased cycle number. (4 ) Comparing witli the post - tensioning prestressed slab track ； the influence of temperature and train load on the vertical deformation of slab ； the stress of slab and the cavity height beneatli the track slab is more significant for CRTS III slab track witli pre - tensioning slab. (5) The research results can provide the experimental basis for the design and maintenance of the CRTS III slab track.