高含冰量冻土的融化压缩变形机理

Mechanism of Thaw Compression Deformation of Ice-rich Frozen Soil

基于目前冻土融化压缩变形计算中较少考虑水分影响的研究现状,充分考虑了温度、水分、应力的影响,通过引入场变量孔隙比e,构建了高含冰量冻土的融化压缩变形理论模型。室内试验与数值计算结果对比发现,理论模型较为准确地反映了高含冰量冻土的变形过程,验证了模型的正确性。试验及计算结果表明,高含冰量冻土的融化压缩变形是复杂的水、热、力多因素共同作用的结果;高含冰量冻土的变形主要是由冻土融化压缩排水所引起,其变形在融化排水过程中基本完成,逐渐趋于稳定,这部分变形是冻土变形的主要构成部分;冻土的融沉特性决定了冻土的变形规律,这也是高含冰量冻土融化压缩变形的本质所在。

There are some inadequacies in current calculation of thaw-compression deformation of frozen soil without the influence of moisture. Considering the effect of temperature coupled with moisture and stress and introducing a field variable of void ratio e, the model of thaw compression deformation of ice-rich frozen soil was established. By comparing the numerical calculation result with experimental result, it can be seen that the theoretical model exactly reflected the deformation process of ice-rich frozen soil relatively, which verified the correctness of the model. The test and the calculation results indicate that （ 1 ） the thaw compression deformation of ice-rich frozen soil is the result from the combined action of several factors such as temperature, moisture and stress; （2） the deformation of ice-rich frozen soil was mainly due to thaw- compression-drainage （TCD） process of the frozen soil and the deformation was tending towards stability, in which the deformation process mas basically finished, and the deformation in TCD process accounts for the most part of the total deformation of frozen soil ; （3） the thaw settlement property of frozen soil determined its deformation regularity, which is the essence of thaw compression deformation of ice-rich frozen soil.