考虑干密度影响的人工压实非饱和黄土渗透系数的试验研究

首先室内配制不同干密度的压实黄土土样，采用水平土柱入渗法测得到不同干密度黄土水分扩散率与体积含水量的关系。结果显示：当含水量较大时，干密度对黄土扩散率的影响非常显著；当含水量较小时，土体水分主要以结合水形态存在，干密度对黄土扩散率几乎无影响。然后采用高速离心机法测试得到不同干密度黄土土-水特征曲线，并分析确定非饱和黄土比水容。进一步回归得到黄土水分扩散率与干密度的关系及考虑干密度影响的非饱和黄土渗透系数的确定方法。最后分析非饱和黄土渗透系数随干密度和含水量的变化规律，结果表明，渗透系数随着含水量的增大而单调加速增大，密实黄土的渗透系数对干密度的变化比较敏感。

EXPERIMENTAL STUDY ON PERMEABILITY COEFFICIENT OF ARTIFICIALLY COMPACTED UNSATURATED LOESS CONSIDERING INFLUENCE OF DENSITY

Water diffusion ratio of unsaturated loess considering the influence of density is studied by test. The test data show that the variation of soil density, for loess with higher water content, can result in great change of diffusion ratio. For the loess with lower volumetric water content, the variation of soil density can result in less change of diffusion ratio. Furthermore, for loess samples with different densities, the matrix suction of the unsaturated loess with different volumetric water contents is tested. On the basis of analysis of test data, the relationship between water diffusion ratio and density of unsaturated loess is explored, and the specific water volume of loess is given. The formula is got to define the seepage coefficient of unsaturated loess considering the influence of density. After analyzing the change law of permeability coefficient resulting from the change of soil volumetric water content and density, it is pointed out that the permeability coefficient of the unsaturated dense loess is sensitive to soil density change compared with loose loess.