Experimental Study Of Unsaturated Silty Clay Shear Strength And Its Impact On Slope Stability Analysis

The strength characteristics of unsaturated soil is hot and difficult in soil mechanics research at home and abroad today. It’s extremely commonof the engineering accident and construction waste caused by the strength of unsaturated soil problems. Therefore, it is necessary to do a more in the strength characteristics of unsaturated soil research.The goal of this study is to understand the basic physical and compression characteristics of unsaturated silty clay and the shear strength characteristics which include the affect of the water content, dry density and anisotropy to the shear strength of unsaturated silty clay. Analysis the relationship of the non-saturated residual slope soil, artificial fill slope stability and the shear strength characteristics. Verify the practicability of the method which presented in this paper. The main work and the results of this article as follows:(1) Through the indoor trials research and analysis of soil samples to get the basic physical properties and compression characteristics and find the method of the test sample.(2) Most unsaturated soil strength theory formula contains suction items to reflect the strength which suction contribution, but the suction control test is costly and time-consuming. In the actual project, it’s directly to study the relationship of the unsaturated soil shear strength index and the water content because of the water content of the soil is easier to determine, so it can establish the shear strength formula which include the water content. Although this method is empirical and approximate. but it is relatively practical, also prevents suction measurement. However, it’s easily and accurately to determine its strength if you know the the distribution of the water content in the practical engineering. Therefore, based on the total stress intensity formula of the unsaturated soil we analyze the affect of the water content, dry density and anisotropy to the shear strength characteristics of unsaturated silty clay by the indoor direct shear tests. From the point of view of the shear strength index we get the anisotropic of the remodeling unsaturated silty clay.(3) Geo_slope is a professional, efficient and powerful analog simulation software which is appropriate application to Geotechnical engineering and geotechnical environment. In this paper, based on the geo_slope software we obtain the unsaturated soil slope stability safety factor that under different water content through taking the different water content which correspond the shear strength index of the unsaturated soil to the slope stability analysis and by the fitting formula of water content and shear strength parameters through the total unsaturated soil stress intensity formula. This method can be a good use of the Mohr-Colum strength formula, bypassing seeking unsaturated soil pore water pressure and, to consider the impact of changes in factors with the water content of unsaturated soil matric suction, but also to ensure that the method engineering practicality. By this method we get the affect of the water content, dry density to the slope stability of the artificial fill and residual talus soil.(4) Trough analysis of two engineering examples about the artificial fill and residual talus soil of the unsaturated soil we determine the practicability of this method.