A new structure to control frost boiling and frost heave of embankments in cold regions

Frost boiling and frost heave are the main factors that cause road damage in cold regions. A new kind of embankment structure, which consists of geotextile, crushed-rock layer and geomembrane, was designed and investigated both in the laboratory and at the field of Budongquan located at Qinghai–Tibet Plateau. Comparison tests were conducted at the same time. The key of the new structure is the porous crushed-rock layer which has smaller thermal conductivity with function of drainage and blocking of moisture migration induced by freezing. Both the laboratory and field research results show that the frost penetration and thawing depths of the new structural embankment are much smaller than those of the coarse-grained soil embankment. Also, the new embankment structure has lower water content in the upper layer and smaller frost heave and thawing settlement than the latter does. In addition, it has good drainage effect. Water coming from the road surface can be drained away from the embankment through the porous crushed-rock layer. All these states that the new structure consisting of the porous crushed-rock layer is superior in frost damage mitigation to the normal structure used in cold regions.