压实黄土强度及渗透各向异性研究

为揭示各向异性对黄土强度和水分场的影响,通过抗剪强度试验和渗透试验对压实黄土强度和渗透各向异性进行研究。结果表明:压实黄土存在强度各向异性,其垂直方向强度参数大于水平方向;压实黄土粘聚力各向异性随含水率增大而减小,干密度对压实黄土粘聚力各向异性无显著影响;含水率和干密度对压实黄土内摩擦角各向异性均无显著影响;压实黄土存在渗透各向异性,水平方向渗透系数大于垂直方向;压实黄土渗透系数随着干密度、围压的增大而减小,且增大到一定程度后变化趋于平缓;干密度、围压对压实黄土渗透各向异性都有较大影响,随着干密度和围压的增大,压实黄土的渗透各向异性会逐渐削弱。

Anisotropy of Strength and Permeability of Compacted Loess

To reveal the influence of anisotropy on strength and moisture field of loess, the strength and permeability anisotropy of compacted loess were studied by laboratory tests. The shear strength of compacted loess was studied by directly shearing tests and the permeability coefficient of compacted loess were studied by permeation tests. The result shows that the strength anisotropy of compacted loess is anisotropic. The cohesion and interior friction angle of compacted loess in the vertical direction are greater than that of the horizontal direction. The cohesive anisotropy of compacted loess decreases with the moisture content increase. The effect of dry density on the cohesive anisotropy of compacted loess is not obvious. The effect of moisture content and dry density on the anisotropy of internal friction angle is not obvious. The permeability anisotropy of compacted loess is anisotropic. The permeation coefficient of compacted loess in the horizontal direction is greater than that of the vertical direction. The permeation coefficient of compacted loess decreases with the dry density or confining pressure increase, and the change tends to be gentle when they increase to certain content. Dry density and confining pressure have great influence on the anisotropic permeability of compacted loess. The permeability anisotropy of compacted loess decreases with the dry density or confining pressure increase.