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高温-高含冰量冻土属于塑性冻土,荷载作用下具有较强的压缩性.为了研究高温-高含冰量冻土的压缩变形特性,采用恒温-变载的试验方法得到了不同温度(-0.3、-0.5、-0.7、-1.0、-1.5℃),不同含水量(40%、80%、120%)条件下冻土试样的体积压缩系数.结果表明:1)高温-高含冰量冻土具有极大的压缩性,青藏黏土40%含水量试样在-0.3℃时的体积压缩系数可达0.328 MPa-1,属于高压缩性土;2)高温-高含冰量冻土在压缩过程中存在渗滤变形,且主要发生于加载的初始阶段;3)温度与含冰量是影响高温-高含冰量冻土压缩性的主要因素,它们决定了冻土中体积未冻水的含量,从而控制了冻土的压缩性;4)在试验条件下,高温-高含冰量冻土的压缩性随着温度的升高而增大,随着含水量的增大而减小.高温时含水量对压缩性的影响比较显著,低温时影响较小.
High temperature - high ice content permafrost belongs to plastic permafrost, which has strong compressibility under load.In order to study the compressive deformation characteristics of high temperature - high ice content permafrost, different temperature (-0.3, -0.5, -0.7, -1.0, -1.5 ℃) and the volumetric compressibility of frozen soil samples under different water contents (40%, 80%, 120%). The results show that: 1) The compressibility of 40% moisture content samples of Qinghai-Tibet clay at -0.3 ℃ is 0.328 MPa-1, which belongs to high compressibility soil. 2) The high temperature-high ice content permafrost And deformation mainly occurs at the initial stage of loading. (3) Temperature and ice content are the main factors affecting the compressibility of high temperature-high ice-rich frozen soils, which determine the volume of unfrozen water in the frozen so as to control the freezing Soil compressibility; 4) Under the experimental conditions, the compressibility of high temperature-high ice content frozen soil increases with temperature, decreases with the increase of water content. The effect is more significant, with less effect at low temperature.