考 虑 温 度 效 应 的 冻 结 膨 胀 土 统 计 损 伤 模 型

In order to study the low temperature mechanical properties of expansive soil in the alpine deep seasonal permafrost region，the consolidation undrained shear tests under low confining pressure in different freezing temperatures，moisture content and freeze-thaw cycles were carried out. The results show that the stress-strain curves of the frozen expansive soil change from hardening to softening with the decrease of freezing temperature and initial water content. The effect of freeze-thaw cycles intensifies the softening effect and promotes the sensitivity of confining pressure. When the freezing temperature is within the frozen zone，the shear process of frozen expansive soil can be divided into four stages with the increase of axial strain：elastic stage，plastic shear shrinkage stage，plastic dilatancy stage and failure stage. The elastic modulus of frozen expansive soil increases with decreasing temperature and presents a good linear correlation. The statistical damage model of frozen expansive soil considering the influence of temperature was deduced，and the law of macroscopic mechanical properties deterioration of frozen expansive soil was revealed.