Submicroscopic Analysis on Deformation Characteristics in Creep Process of Frozen Soil

In this paper, computerized tomography (CT) is used to measure and analyze the change of submicrostructure of frozen soil in uniaxial and triaxial creep process. The study reveals that the strengthening and softening actions of structure, as well as the form characteristics of creep process in frozen soil are controlled by growing microcracks, and growing and extending structural damage in creep process. The broken structure was appeared firstly in weak area of low density layer of sample. In uniaxial creep process of frozen soil, a ringlike zone of low density was formed in weak layer of sample and then extended outward to result in failure of integral structure. And the volume of frozen soil increased continuously with time. In triaxial creep process of frozen soil, the tensile cracks was formed in surface of low density part of sample and then extended inward to result in failure of integral structure. Meanwhile, the volume of frozen soil decreased continuously and increased slightly at the third creep stage, but it was still smaller than the initial value.