黏土土水特征曲线的实验研究及理论分析

Theoretical Analysis and Experimental Study of Clay Soil Water Characteristic Curve

采用压力膜仪测定了不同击实干密度非饱和黏土的土水特征曲线,分别用van Genuchten、Brooks&Corey和Log-Normal Distribution模型对干密度为1.3 g/cm3的黏土试样土水特征曲线进行拟合比较,结果表明,van Genuchten模型能更好地拟合实验结果,同时给出了拟合参数。并用van Genuchten模型对不同干密度黏土试样土水特征曲线进行拟合,通过分析比较得出:土体干密度越大,空气进气值越高,土水持水能力越强。含水率相同时,土体基质吸力随干密度的增大而增大;对某一特定干密度土体的土水特征曲线,高含水率段基质吸力随含水率变化幅度小,低含水率段基质吸力随含水率变化幅度大。

The soil water characteristic curve of different compactive dry density of unsaturated clay was measured using pressure membrane, respectively van Genuchten, Brooks and Corey and Log-Normal Distribution model on the dry density of1.3 g/cm3Clay soil water characteristic curve was fitted, The results show that the van Genuchten model can well fit the experimental results at the same time, the fitting parameters are given. And the clay samples with different dry density of soil water characteristic curve were fitted with van Genuchten model, obtained by analysis and comparison: the dry soil density,the higher the value of the air inlet, water and soil water holding capacity is higher. At the same soil water content, the matrix suction increases with dry density incre asing; for a particular dry density of soil water characteristic curve, high water cut period of matric suction with water content changes are small, low water cut segment matrix suction with water content variation.