关键词: 冻结砂土, 单轴压缩, 破坏应变, 线弹模量, 应变率, 含水率

Abstract: Based on a mud method of preparation sample, some uniaxial compressive tests are conducted on the frozen silty sand samples prepared with the mud sample preparation method. The failure strain and linear elastic modulus characteristics of frozen silty sand under uniaxial compression are investigated systemically in a wide range of strain rate and water content. The experimental results show that with rise of strain rate, failure strain increases gradually when water content is 12.0%; failure strain firstly increases and then decreases with growth of stain rate when water content is between 16.7% and 24.0%; when water content is greater than or equal to 30.6%, with increasing strain rate, failure strain decreases gradually; for the above three cases, the failure strain always tends gradually to be stable in the end. With increasing water content, failure strain firstly increases to a maximum sharply and then decreases dramatically. The failure strain tends to the failure strain of ice after water content is beyond 41.5%. Linear elastic modulus increases nonlinearly to a peak with increasing water content and then further rise of water content makes it lower, which can be described by a quadratic polynomial model. At 2.0 ℃, when strain rate less than 4.67×10-3 s-1, with increase of water content, linear elastic modulus increases nonlinearly and then tends to the linear elastic modulus of ice; when strain rate greater than or equal to 4.67×10-3 s-1, linear elastic modulus firstly increases to a maximum and then decreases to the linear elastic modulus of ice with increase of water content. When temperature is at 5.0 ℃, the similar critical value of strain rate to 4.67×10-3 s-1 is 1.00×10-2 s-1.

Key words: frozen silty sand, uniaxial compression, failure strain, linear elastic modulus, strain rate, water content