Analysis of frost heave on subgrade in permafrost regions

By simulating the changing progress of climate features,the thermal regime of subgrade in permafrost region in each month is got. The variations of thermal regime with time indicate the variations of frost soil body. Then,on the basis of the thermal elastic theory in which the tensile failure is taken into account,authors attain the deformation features of subgrade in the permafrost region with consideration of body force and frozen-heave force. Furthermore, the cause of formation for the longitudinal cracks in subgrade is explored. And it is exposed that the longitudinal cracks primarily arise in the central section of the subgrade and in the position near road shoulder. This is identical to the situation in site. It is indicated that the building subgrade with low frost heaving soil, example for sandy gravel, is beneficial to prevent longitudinal cracks developing.