Influence Of Springs Outflow Along With Soil On The Properties Of Loess At The Back Edge Of Heifangtai Landslide

This paper takes Heifangtai's loess slope in Yongjing County of Gansu Province as the research object,select three sampling areas in the loess landslide area where the springs are exposed,take the spring as the center and take soil samples in the surrounding area in sequence,use constant head method,drying methed,cutting ring methed and laser particle size analysis instrument method to measure soil samples'saturated hydraulic conductivity,water content,dry bulk weight,and mechanical composition indoors.Study the variation of these main physical properties of loess with the increase of the distance from spring,analytic the regularities of statistics distribution by traditional statiscal methods,and we can study it that the outflows of the spring and the soil will affect the main physical properties of loess.The main conclusions are as follows:?1?In all sampling points,the saturated hydraulic conductivity is in the range of 10^-5 to10^-3 cm/s,the water content is in the range of 3 to 27%,the dry bulk weight is in the range of0.9 to 1.6 g/cm³,the mechanical composition is in the range of 32 to 47?m.The vertical hydraulic conductivity is bigger than horizontal hydraulic conductivity in most sampling points,the saturated hydraulic conductivity of loess has obvious anisotropy;?2?Take the spring as the center,follow the slope from bottom to top along the vertical direction of the slope,as the distance from the spring point increases,the vertical and horizontal saturated hydraulic conductivity gradually increase.The water content is very high in a range close to the spring point,and decreases sharply as the distance from the spring point increases,outside a certain distance,the changes are more gradual,the dry bulk weight and the average particle size are generally reduced,but there are also specific areas;?3?Take the spring as the center,along the direction 45 degree left?right?deviation from the vertical direction,as the distance from the spring increases,the saturated hydraulic conductivity first increases and then decreases,and the water content drops first,then decreases slightly,or is basically unchanged,there is no obvious regularity in the dry bulk weight,but the change of dry bulk weight is consistent in the same sampling area,the average particle size has a smaller decrease or is basically unchanged?4?Centered on the point of the spring,along the horizontal direction,the saturated hydraulic conductivity increases within a certain range,and the water content decreases within a certain range,the dry bulk weight and the average particle size are larger than those near the spring;?5?For the correlation between the various properties,there are differences between the three sampling areas,however,there is always a negative correlation between the water content and the distance from the spring,and there is always a positive correlation between the vertical saturated hydraulic conductivity and the horizontal saturated hydraulic conductivity,and there is always a negative correlation between the dry bulk weight and the hydraulic conductivity;?6?The saturated hydraulic conductivity and the water content have moderate variability,the dry bulk weight and the average particle size have weak variability,the kurtosis values of the saturated hydraulic conductivity,the dry bulk weight and the average particle size are all less than 3,and they are flat distributions,the kurtosis value of the water content is greater than 3,and it is a sharp distribution;...