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对饱和冻结和林黄土在-2℃的温度条件下进行了单轴压缩试验和围压范围为1~5 MPa的三轴压缩试验.试验结果表明:单轴压缩的应力应变曲线为应变软化型曲线,而三轴压缩试验中各围压下的应力应变曲线均为应变硬化型曲线,围压主要影响冻结和林黄土的初始变形行为,而对后期的变形影响不大;各围压下冻结黄土的体积应变都呈现出先体缩后体胀的特征,总体变均较小;围压对冻结和林黄土的屈服极限和强度影响不大;研究了初始切线模量的确定方法,用修正的Duncan-Chang模型对不同应变范围内的试验数据进行拟合,并由此确定了相应的初始切线模量,发现在0~4%应变范围拟合试验数据确定初始切线模量最为合理.
The uniaxial compression test and the triaxial compression test with confining pressure range of 1 ~ 5 MPa were carried out under the condition of saturated freezing and forest loess at -2 ℃ .The results show that the stress-strain curve of uniaxial compression is strain softening While the stress-strain curves under confining pressure in triaxial compression test are all strain hardening curves. The confining pressure mainly affects the initial deformation behavior of freezing and forest loess, but has little effect on the deformation in later stage. The volumetric strain of loess shows the characteristics of body shrinkage after body shrinking, and the overall change is small. The confining pressure has little effect on the yield strength and ultimate strength of frozen soil and forest loess. The method of determining the initial tangent modulus is studied, The Duncan-Chang model was used to fit the experimental data in different strain ranges, and the corresponding initial tangent modulus was determined. It was found that it was reasonable to determine the initial tangent modulus by fitting the experimental data in the strain range of 0-4%.