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About 23% of the earth’s surface is permafrost area. About 21.5% of China’s land area is permafrost area, which makes China the world’s third largest permafrost area country. Seasonal frozen soil is a spescial kind of soil with ice-water system. According to studies, most mid-latitude regions on Earth are affected by seasonal freezing and melting. In China, seasonal frozen soil mainly distributes in the latitude of 30°N, which vers 53.5% area of China’s land area.Early damage of pavement, diseases of embankment and pavement materials under special geographical conditions have become the bottlenecks of the construction of infrastructure. Some proper methods to solve these problems are badly needed. Accelerated Loading System is able to simulate vairous environmental factors (heat, cold, water, ice, radation, wind, etc.). But because of the large size of the New Type Accelerated Loading System, the accurate simulation of air temperature, road temperature and roadbed temperature are the key points and also difficult points for the system. As there are few reference data, numerical simulation can provide some data which are very important for designing and running the system. By using the software FLUENT, numerical simulations for everfrost are done, and the temperature field inside the roadbed, total working time and total refrigerating capacity under different pipe pitch are carried out. Some design parameters which are not related to the materials of the roadbed are concluded. So by using the numerical simulation, some design parameters and operational parameters are provided.
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