Temperature monitoring of the XPS board insulated subgrade along the newly constructed Gonghe-Yushu Highway in permafrost regions

On the basis of on-site measured data of the newly constructed Gonghe-Yushu Highway in a permafrost region, this paper analyzed thermal conditions of the subgrade with XPS insulated board according to different selected monitoring sections in various locations. We also summarized the geothermal distribution and change rules of subgrade with XPS insulation board under the asphalt pavement in summarized a high temperature frozen soil region. It is suggested that the shoulder of subgrade with XPS insulation board be widen to a reasonable width so as to keep the subgrade stable.