Experimental study on the soil-water characteristic curve of the unsaturated loess in East Gansu province

In order to study the soil-water characteristic curve (SWCC) of unsaturated loess in East Gansu province, the effects of initial dry density and net mean stress on the SWCC of unsaturated loess were studied by a unsaturated soil triaxial apparatus. The results showed that when the matrix suction was the same, the moisture content of samples decreased with the increase in net mean stress. The larger the initial dry density, the smaller was the moisture reduction rate, and the higher was the final moisture content. Through the Van Genuchten model it was found that the residual moisture content theta(r) decreases with the increase in net mean stress; the numerical values of the fitting parameters alpha and n do not change significantly as the net mean stress increases. The initial dry density mainly has an effect on the parameters theta(r) and alpha of SWCC while the parameter n is not much affected.