多年冻土地区路基冻胀变形分析

首先模拟气候因素变化过程,得到不同时期冻土路基温度场分布,温度场随时间的变化可以反映出冻结相变区的变化,然后考虑土体体积力和土体冻结相变产生的冻胀力,采用考虑拉破坏的热弹性力学方法,分析得到多年冻土地区路基变形分布和演变规律;在此基础上,对冻土路基纵向裂缝的成因进行研究,揭示出冻土路基纵向裂缝主要出现于路面中部及路面靠近路肩部位,这与实际情况是相符合的。进一步的分析表明:采用低冻胀性的土填筑路基,如采用碎石土填筑,对于降低冻土路基冻胀变形及防治纵向裂缝病害是有效的。

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.