黄土路基毛细水上升规律试验模拟研究

Numerical and Experimental Study on Capillary Rise of Phreatic Water in Loess Roadbed

针对黄土地区高等级公路路基有害毛细水问题,使用改进后的竖管法对压实度大于90%黄土土柱毛细水上升规律进行了试验研究,得到了毛细水上升高度与干密度的关系.使用滤纸法和水平入渗法测量土样的基质吸力、土水扩散系数与含水率的关系,并用Geostudio软件对毛细水上升进行模拟.试验和模拟结果表明:基质吸力的确定应该同时考虑含水量和密度2种因素;土壤的压实可以有效减缓土壤非饱和水分的运动速度;随着压实度的增加,毛细水上升速度变小;压实度为98%、95%和93%的黄土土柱,在105 d后毛细上升高度分别为74 cm、80 cm和94 cm.Geostudio软件可以用于路基毛细水运动的模拟.

Aiming at the problem of harmful capillarity of highway roadbed in loess region, a research on capillarity rise of loess columns under compacted degree above 90% is conducted by an improved method of vertical tube, and the relationships between the height of capillarity rise and the dry soil density is obtained. The relationships among volumetric water content and the matric suction and volumetric water content of loess sample is obtained from filter paper method and horizontal infiltration column method. The capillarity rise is simulated by using software Geostu-dio. The experimental and simulated results show that both moisture content and density should be taken into con-sideration in the determination of matrix suction. The speed of unsaturated soil water movement is reduced by soil compaction and the speed of the capillarity rise decreases with the increas of the soil compacted degree. After 105 days, under the condition of the compacted degree of 98%, 95% and 93%,the heights of the capillarity rise in soil column are 74 cm, 80 cm and 94 cm, respectively. It is concluded that Software GeoStudio can be used to simulate capillarity rise.