Cooling effect of combined L-shaped thermosyphon, crushed-rock revetment and insulation for high-grade highways in permafrost regions

In order to keep the thermal stability of large-width highway embankment in permafrost regions, a new type of cooling measure of combined L-shaped thermosyphon, crushed-rock revetment and insulation is presented. To examine its cooling effect, laboratory tests are carried out. The test results have preliminarily proved the effectiveness of the new cooling measure. To further validate its effectiveness in the service life of the highways in permafrost regions, based on relative theories and the laboratory test results, a numerical model for the highway embankment is established, and the temperature characteristics of the embankment in its service life are analyzed. The numerical results show that the combination of the L-shaped thermosyphon, crushed-rock revetment and insulation is effective to keep the thermal stability of the large-width embankment in its service life under the condition that the air temperature is warmed up by 2.6℃. Based on this, the new combined cooling measure is suggested to be used in the construction of large-width embankment in permafrost regions.