高压实黄土非饱和土水运动试验模拟研究

Numerical and Experimental Study on the Movement of Unsaturated Soil-Water in High Compacted Loess

摘要: 对于压实度大于90%的黄土，使用滤纸法研究土壤基质吸力同干密度和含水率之间的关系，使用水平入渗法研究非饱和土水扩散率同干密度和含水率之间的关系，使用竖管法研究土样毛细水上升规律，并使用GeoStudio软件进行数值模拟。试验和模拟结果表明：由于压实程度的不同将改变土壤孔隙的结构特征，对土壤的持水特性有较大的影响，基质吸力和非饱导水率的确定应该同时考虑含水量和密度两种因素；土壤的压实可以有效减缓毛细水的运动速度，压实度为98%、95%和93%的压实土柱，在105天后毛细上升高度分别为74 cm、80 cm和94 cm。Geostdio软件可以用于土基毛细水上升的模拟。

Abstract: For loess whose compacted degree is above 90%, the relationship between matric suction and volumetric water content under different compaction conditions is studied by filter paper method, and the relationship between Soil water diffusivity and volumetric water content under different compaction conditions is studied by horizontal infiltration method. The capillary water upward law is studied by vertical tube method, and is simulated by GeoStudio. Results of the experiment and the simulation show that the soil pore structure characteristics is changed due to the different degree of compaction, and influences soil retention ability. Two factors including volumetric water content and density must be considered simultaneously in determining matrix suction and unsaturated soil hydraulic conductivity. With increasing soil compacted degree, the speed of capillarity water movement is decreased. After 105 days, the rising heights of capillary water in soil column are 74 cm, 80 cm and 94 cm in the condition of compacted degree 98%, 95% and 93%, and GeoStudio could be used to simulate capillary water rise.