Thermal State and Effect Analysis of Engineering Measures of High-speed Railway Subgrade in Island Permafrost Region
To reveal the thermal state of the high-speed railway(HSR)subgrade in the island permafrost region and propose effective cooling structures,field monitoring was conducted in the experimental section of a station on the newly constructed Harbin to Yichun HSR to obtain ground temperature data of island permafrost.Subsequently,based on the measured ground temperature data,numerical simulations were performed using hydro-thermal coupling theory to compare the temperature distribution characteristics and cooling effects on the underlying island permafrost of three cool-ing subgrade structures to be implemented at the station.The three structures include ordinary heat pipes subgrade(OHPS)with double rows of heat pipes on both sides,all-season heat pipes subgrade formed by OHPS plus a single row of heat pipes in the center,and all-season heat pipes subgrade formed by OHPS plus a horizontal arrangement of heat pipes at the base.The results show that the average annual temperature and precipitation in the Tieli Region are on the rise,with the ground temperature of the natural site's island permafrost at around-0.3 ℃,which is high-temperature and extremely unstable permafrost.Among the three cooling subgrade structures,the all-season heat pipes subgrade pro-vides the best protection and cooling effect on the island permafrost,while the ordinary heat pipes subgrade performs the worst.The upper limit of permafrost under the ordinary heat pipes subgrade shows a"convex on both sides,concave in the middle"pattern with insignificant uplift,while the upper limit of permafrost under the all-season heat pipes subgrade exhibits an"upward convex gentle slope with a flat top"pattern with significant uplift.The research findings will provide technical support for the construction and structural optimization of HSR subgrade in permafrost regions.
railway subgrade in cold regionisland permafrostordinary thermal pipeall-season thermal pipeupper limit of frozen soil
万方数据
维普
