Embankment frost heave is a persistent problem in railway operation in cold regions.Active heating is an al-ternative way,when traditional waterproof and drainage,soil improvement and thermal insulation measures fail.In this study,a distributed heating system based on ground source heat pump was designed for the K44+970-K45+020 frozen damage section of Jungar-Shenchi railway,and a 20 m long on-site heating section was constructed.A freeze-thaw cycle heating test was carried out in the winter of years 2021-2022,to analyze the heat exchange temperature of heat pump,temperature field of natural and heating embankment,freezing depth and track deformation based on the monito-ring data.The results show that the heating temperature of the heat pumps can reach above 50 ℃,with high heat source grade and stable heating capacity.Both the frozen range and extreme temperature value of the embankment in the heating test section are significantly reduced compared to natural conditions.The maximum freezing depth at the horizontal center of the line is reduced from 148 cm to 88 cm,with the freezing front maintaining above the capillary migration range of groundwater.The freezing depth difference in horizontal direction is reduced from 49 cm in natural conditions to 13 cm,which is conducive to eliminating the horizontal track irregularity caused by lateral frost heave differences.The longitudi-nal freezing depth difference controlled within 20 cm can avoid secondary vertical track irregularity.The natural embank-ment near the test section shows the law of developing deep frost heave first,followed by shallow frost heave during snowmelt infiltration,with a maximum frost heave deformation of 9.4 mm.However,in the test section,deep frost heave has not developed and shallow frost heave is effectively controlled.The deformation of the track,controlled within±3 mm,is within the maintenance management value.The active heating method has effectively alleviated the problem of embankment frost heave in the test section.
维普
万方数据