Experimental study of capillary rise of unsaturated clayey sand

A set of test system for studying capillary rise has been developed by using MP406 moisture probe, WM-1 suction probe and DT80 logger, etc. The system has been used to carry out 3 poles of different initial water contents capillary rise tests on unsaturated clayey sand with controlled 1.7 g/cm(3) dry density. The relationships between different cross-sections water contents and suctions and time are obtained. The results indicate that the initial water content has a great effect on capillary rise hight and rising velocity. This system could measure wetting front advancing velocity at different time and study changing water content and suction of different cross-sections. This system could fix quantity study capillary rising maximum hight and unsaturated hydraulic conductivity to resolve the difficulties that using general methods couldn't measure. It can measure unsaturated hydraulic conductivity according to wetting front advancing velocity, water content changing & suction changing of samples. Coefficient of permeability will be get from soil water characteristic curve. At the same time, the laws of wetting front movement are given under different initial water contents.