关键词: 大温差;无砟轨道;温度场;有限元

Abstract: In view of the early crack and other durability problems of concrete slab of ballast bed after the construction of LanXin second-line ballastless track, 1:1 full-scale model tests in laboratory simulation. Using artificial climate simulation box to simulate the great temperature difference in Northwest China, the cracking mechanism of ballastless track slab of ballastless track is studied from the aspects of distribution, variation and deformation of early hydration heat field, establishing the relationship between the temperature field of concrete hydration temperature and the atmospheric temperature environment in Northwest China.At the same time, the temperature field of hydration heat is simulated by finite element software, and the calculated results are compared with the indoor test results.The results show that: The large temperature difference and abominable environment are the main causes of the cracking of the bed slab.The temperature field and the environmental temperature change periodically.Closer to the surface of bed plate, the larger temperature gradient is, the more likely to create cracks.

Key words: large temperature difference;ballastless track;temperature field;finite element