关键词: 高温-高含冰量冻土, 应力-应变关系, 破坏类型, 抗压强度

Abstract: In order to study the strength character of warm and ice-rich frozen soil, a series of uniaxial compressive strength tests of frozen clays with water contents of 20 %, 40 %, 60 %, 90 %, 120 % at temperatures of –0.3 ℃, –0.6 ℃, –0.9 ℃, –1.5 ℃, –5.0 ℃ were conducted respectively. The test results indicate that: 1) the type of stress-strain curves for the warm and ice-rich frozen clays(temperature: –0.3 ℃ to -1.5 ℃, water content: 60 %-120 % ) is strain-hardening, and the form of sample failure is plastic; 2) The compressive strength of warm frozen clay with water contents of 40 % to 90 % increases linearly with the decrease of temperature, the sensitivity of the strength of lower water content saturation frozen clay to temperature is higher than that of higher water content saturation frozen clay; at the water content of 120 %, the amplitude of the increase in compressive strength decreases with decreasing temperature; 3) when the temperature of the warm frozen clay is lower than -0.9 ℃, there is a most disadvantageous water content (at the same temperature, the compressive strength of the frozen soil at this water content is the lowest); when the temperature of the warm frozen clay is higher than -0.6 ℃, the strength increases with water content increasing.

Key words: warm and ice-rich frozen soil, stress-strain relation, failure type, compressive strength