压实黄土强度和变形各向异性的试验研究

Experimental research on strength and deformation anisotropy of the compacted loess

为研究各向异性对压实黄土强度和变形特性的影响,分别对由垂直向和水平向切取的压实黄土试样,进行了不同围压、不同干密度和不同含水率下的真三轴剪切试验.试验结果表明:相同围压、干密度下,垂直向和水平向的应力-应变曲线有明显差异,垂直向试样的轴向应变小于水平试样.轴向应变差异随着干密度和轴向压力的增大而增大,随着含水量和围压的增大而减小;侧向应变差异随着干密度和轴向压力的增大而增大,随着围压的增大而减小.初始变形模量Ei在垂直方向大于水平方向,抗剪强度在垂直方向大于水平方向.

In order to study the effect of anisotropy on the strength and deformation characteristics of compacted loess, the strength and deformation anisotropy of compacted loess were studied by true triaxial tests with the different confining pressure, dry density and the moisture content. The test results show that under the same stress and dry density, there are significant differences between the vertical samples and the horizontal samples, and the axial strains of vertical samples are greater than the horizontal samples. The differences of axial strain increase with the increasing of dry density and axial stress, and decrease with the increasing of confining pressures and the moisture content. The differences of lateral strain increase with the increasing of dry density and axial stress, and decrease with the increasing of confining pressures. The initial deformation modules of the vertical samples are higher than that of the horizontal samples. The shear strength of compacted loess in the vertical direction is larger than that in the horizontal direction.