Study On The Temperature Field Of Thermal Probe Subgrade In The Permafrost Regions

Thermal probe subgrade is one of the special project measures to protect subgrade permafrost cap don't fall in permafrost region. This article bases on the indoor thermal probe test, on-site road condition investigation, field testing and the numerical simulation to research the cooling effect of thermal probe subgrade and its temperature field, obtain a series of research results:(1) Takes indoor thermal probe test, analyses the work efficiency of the thermal probe in different temperature range, determines the starting temperature difference and heat transmission effectiveness. The test shows that the starting temperature of thermal probe is 5℃, the heat transmission effectiveness is 0.9364kj/min.(2) Investigates the diseases of thermal probe subgrade in permafrost region, using manual power touch agent to tests carrying capacity of shoulder and slope, analyzes the disease causes from water and heat angle.(3) Through finishing the test data of test section on WuDaoliang area of the qinghai-tibet plateau, analyzes the work period and the maximum thawing depth variation characteristics of the thermal probe subgrade. The test data shows that the cooling effect of the thermal probe subgrade is obvious. It is good to protect the permafrost layer under the subgrade.(4) According to the governing equation of temperature field, this article builds the temperature field model of thermal probe subgrade. Combined with the boundary conditions of testing road, article simulates the thermal probe subgrade numerically, proves the correctness of the simulation, simulates the temperature field on thermal probe subgrade in the after ten years and analyzes the internal temperature variation characteristics of thermal probe subgrade.(5) According to the numerical simulation results and the subgrade design principles in permafrost regions brings up the design principles of the thermal probe subgrade.