中文摘要：

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.

英文摘要：

A uniaxial compression test and a series of triaxial compression tests with confining pressures from 1to 5 MPa were conducted on saturated frozen Helin Loess at-2 ℃. The experimental results indicate that stressstrain curves under uniaxial compression show strain softening phenomenon,while strain hardening phenomena appear in the stress- strain curves under different triaxial compressions. The influence of confining pressures on the initial deformation behavior of frozen loess is obvious,but the later deformation behavior is hardly affected by the confining pressures. The volumetric strains under various confining pressures are compressed at the beginning and then shift to be expanded. But the volumetric strains are small as a whole. The yield limit and strength of frozen Helin Loess are hardly affected by confining pressures. A method to determine the initial tangent modulus was investigated. The modified Duncan-Chang＇s model was adopted to fit the test data under different ranges of strain and to determine the initial tangent modulus. It is found that the most reasonable range of strain for fitting the test data and determining the initial tangent modulus is 0 ～ 4%.