关键词: 高含冰冻土, 变形特性, 单轴抗压强度, 应变率, 初始含冰量

Abstract: On the basis of a series of uniaxial compressive tests on frozen silty sand under different initial ice contents and strain rates, the uniaxial compressive deformation and strength characteristics of frozen silty sand are discussed and analyzed. The results show that with the initial ice content increasing, the plasticity of frozen silty sand is enhanced and the stress-strain behavior gradually tends to the characteristic of remolded ice after the initial ice content increases above 210.1%, and the relationship between stress and strain can be described by using the revised Duncan-Chang model. With initial ice content increases, the initial tangent modulus of frozen silty sand nonlinearly rises when the strain rate is 0.083×10-3 s-1 or 0.467×10-3 s-1; but it originally increases to a maximum value and then begins to decrease when the strain rate is 0.667×10-3 s-1. A log function can be used to describe the relationship between the uniaxial compressive strength and initial ice content, that is, the strength first increases and then gradually tends to be stable as the ice content augments from 32.9% to 304.0%. This study can supply a basis for evaluating the stability of subgrade in permafrost region with ice-rich soil.

Key words: ice-rich soil, deformation characteristic, uniaxial compressive strength, strain rate, initial ice content