Laboratory investigation on the cooling effect of the embankment with L-shaped thermosyphon and crushed-rock revetment in permafrost regions

The road construction engineering in permafrost regions and global warming can both induce warming, even thaw permafrost, which exert great influence on the embankment stability. A series of cooling technique, e.g. insulation, crushed-rock revetment and thermosyphon, has been proved to be effective to keep the thermal stability of embankment. However, almost all of the present cooling measures are limited to the embankment of ordinary width. Since the heat intake of the embankment increases greatly due to the width and asphalt pavement for high-grade highways of large width, the traditional cooling measures may be inadequate to protect the underlying permafrost and ensure the stability of the embankment. Because of these factors mentioned above, an L-shaped thermosyphon was presented, and was applied to the wide-width embankment with crushed-rock revetment and insulation. A laboratory test was carried out to investigate the joint cooling effect of this new kind of embankment and the property of the L-shaped thermosyphon. Laboratory test results indicate that the combined measures, presented in the paper, is able to keep the thermal stability of large-width embankment in cold regions.