Characteristics Of Loess Saturated Hydraulic Conductivity In Yao County Loess Plateau

The hydraulic conductivity of loess is a very important parameter in the hydrogeologic parameters of loess.It is of great theoretical significance to study the geological hazards such as landslides,wet traps and other geological hazards caused by water infiltration.Taking Yao County loess tableland area for research,selected the Yao County loess tableland five drilling core soil samples as the research object,based on the available drilling core sample,respectively,selected the 5 and 6 in the residual tableland borehole core soil sample no.4 and no.12,sichuan tableland area borehole core soil samples and 16 borehole core soil samples in the valley indoor variable head used in the determination of saturated hydraulic conductivity.Through the measured horizontal hydraulic conductivity and vertical data,using negative exponential function fitting saturated permeability coefficient changing with the depth of loess,using the traditional statistics and statistical methods to analyze the spatial variation of the hydraulic conductivity of loess characteristics,for all kinds of geological disasters caused by the hydraulic conductivity of loess to provide scientific theory basis.The main conclusions are as follows:(1)Selected five drilling cores saturated hydraulic conductivity of soil sample range within 10-3m/d~ 101m/d,the saturated hydraulic conductivity of loess has obvious anisotropy,and vertical hydraulic conductivity is bigger than the horizontal hydraulic conductivity;(2)The loess saturated hydraulic conductivity decays with depth as a whole.Malan loess’ s saturated hydraulic conductivity is obviously greater than lishi loess’ s.The use of the five drilling figure negative exponential function fitting different strata of hydraulic conductivity changing with the depth that malan north of saturated hydraulic conductivity that increases with the increase of depth,the hydraulic conductivity of lishi loess increased with the increase of depth of gradually diminishing;(3)Using traditional statistical gumethods and statistical methods to analyze data,the saturated hydraulic conductivity has the obvious variation of loess,but the horizontal hydraulic conductivity of variability and the vertical hydraulic conductivity of variability is not obvious difference.Whether it is the vertical hydraulic conductivity or the horizontal hydraulic conductivity,the lognormal distribution is obeyed;(4)To statistical methods can be used to see gauss model is more suitable for drilling,drilling hole 4,hole5 and 16 of the loess saturated hydraulic conductivity,the spherical model was more suitable for fitting of no.6 drilling loess saturated hydraulic conductivity,and the exponential model is more suitable for fitting the 12 th hole of loess saturated hydraulic conductivity.The hydraulic conductivity of any two points of the yellow soil is correlated,and the spatial correlation is stronger.The relative distance of the vertical hydraulic conductivity is between 62 m and 72 m,the relative distance of the horizontal hydraulic conductivity is 3m,the maximum 70 m.The spatial correlation and homogeneity of loess saturation vertical hydraulic conductivity are better than the horizontal hydraulic conductivity.