The Research And Application Of Soil Water Characteristic Curve Of Cohesive Clay In Yangzhou

Soil-water characteristic curve (SWCC) is an important constitutive relation on unsaturated soil, It expresses the relationship between soil moisture content and suction.We can get the permeability function of soil, the deformation and the strength from the SWCC. In the field of geotechnical engineering, Evaluation of slope stability and prediction of rainfall-induced landslide usually need to use the relevant theory of soil-water characteristic curve. So SWCC is very important of unsaturated soil research. In this paper take typical silty clay at Yangzhou for study, a series of texts were carried out for Soil-water characteristic curve by using GDS unsaturated triaxial apparatus. And getting analysis of slope stability under the condition of rainfall infiltration On the basis of the test results.The main conclusions are summarized as follows:(1) Collect and summarize previous research date of Soil-water characteristic curve, make clear the test method, influence factors, and the curve equation of SWCC.(2) The GDS automatic triaxial apparatus is used to measure the soil-water characteristic curve, through the texts analysis of the differences in the soil water characteristic curves for different dry densities, different confining pressure and different soil. The results are summarized as follows:Confining pressure effect on soil water characteristic curve is not big; The greater the dry density, the greater the air entry value, the smaller the rate of dehydration; The larger the soil clay content, the greater the air entry value, the smaller the rate of dehydration.(3) Using three parameter model of Fredlund and Xing to fit the equation and analyzing for The fitting parameters, the corresponding range is given.(4) Based on the soil water characteristic curve, simulated rainfall process, analyzed the safety of slope of cohesive soil in Yangzhou under rainfall. The results are summarized as follows: Under the same matric suction, the greater the water content, the greater the permeability coefficient, the greater the depth of rainfall infiltration; The greater the air entry value, the greater the permeability coefficient, so as to improve the initial slope safety factor. After4days of heavy rainfall, The slope safety factor of Yangzhou cohesive soil drop about30%-50%, The sliding surface in the slope surface.