Hydraulic Conductivity Variation Of Loess Slope In Southern Tableland Of Jingyang

The permeability of unsaturated loess is an important part of its properties. The research on loess permeability in different directions is particularly important to determine the range of loess collapse and the study of loess landslides caused by the infiltration of water in the loess.This research took Jingyang section as the study area, choose the loess shape of Zhaitou village and Jiangliu village as the research object. In the trench of Zhaitou loess shape set total 22 text locations in the vertical direction. In the loess cave of Jiangliu set total 12 text locations in the horizontal direction. The saturated hydraulic conductivity is measured by falling head permeability test. Then we used the Lillietest to determine the normality of K values and adopted the methods of geostatistics and traditional statistics to research the spatial variability of hydraulic conductivity. Through the determination of Soil-Water Characteristic Curv to calculate the unsaturated hydraulic conductivity, analyze its relationship of the unsaturated hydraulic conductivity and water content for the loess. The main contents focused on the following aspects:(1) falling head permeability test calculating the average Kv, Kh of loess shape is 3.23×10-4cm/s and 1.70×10-4cm/s, calculating the average Kv, Kh of loess cave is 3.23×10-4cm/s and 1.29×10-4cm/s. The hydraulic conductivities have a stone spatial variability.(2) Kv, Kh values of loess shape and Kv, Kh values of loess cave were not in normal distribution;after logarithmic transformation, those of loess cave and loess shape were in normal distribution.(3) Adopting the traditional statistics, the Kv and Kh of the two place belong to moderate variability. Adopting the methods of geostatistics, for Kv, Kh values of loess shape and Kv,Kh values of loess cave, trandom factor influence is weak, variability is mainly composed of the structural loess itself. Kv variation value is greater than the variation of Kh, correlation between vertical direction than in horizontal direction.(4) Loess saturated permeability coefficient has a tendency to increase with depth decreases, but within each stratum permeability distribution has a strong variability. Loess saturated permeability coefficient has a tendency to increase with depth decreases, but within each stratum permeability distribution has a strong variability.