Unsaturated Red Clay Shear Strength Characteristics Of Its Applications

The study of unsaturated soil is the hotspot and difficulty of soil mechanics,and the study of strength of unsaturated soil is quite significant.In the paper,formers' works in strength theory and test of unsaturated soil have been summarized.The shear properties of unsaturated red clay is studied by test and applied to the solution of soil slope stability.The primary works in this paper are presented as follows:1. The importance of the study of unsaturated soils is emphasized.The basic characteristics of unsaturated soils,concept of matrix suction,and the research history and present situation of unsaturated soils are simply introduced.2. The shear strength is one of the most important research fields of the unsaturated soils. The research history and present situation of strength theory and test of unsaturated soils are simply introduced.3. With matrix suction of specimen controlled,the consolidated drained triaxial tests were carried out for the unsaturated red clay of Xianning in Hubei province by triaxial test system for unsaturated soil to study the relationship between shear strength and matrix suction of specimen and present the formula on strength of the unsaturated red clay.4. Slope stability of cohesive soil is significantly influenced by rainfall.The most important cause of landslide taking place in rainy season is that the increase of moisture content makes the matrix suction of soil decreased thus reduces the shear strength.With the change of matrix suction caused by unsaturated unsteady seepage and influence of matrix suction on shear strength considered,the stability of a simple slope under rainfall is calculated.