Comprehensive Research On Expansive Soil In Hefei

This paper carries out a comprehensive research on the expansive soil of Hefei.Based on the existing expansive soil classification methods are summarized, the expansive soil in Hefei is obtained for medium weak expansive soil. Through the formation of Hefei region studied, we get the distribution and the depth and thickness of expansive soil in different positions in Hefei, and explain the causes. By means of laboratory tests on soil samples taken from different positions, it comes out a series of physical and mechanical parameters such as density, dry density, moisture content, liquid limit, plastic limit, free expansion, maximum dry density and optimum moisture content, cohesion and internal friction angle of Hefei expansive soil.And we also obtain the variation of the physical and mechanical properties of expansive soils in different locations in Hefei. By Studying the mineral composition and chemical composition of Hefei expansive soil, the relationship between mineral composition and the boundaries moisture content is concluded. Using polarized light microscopy and SEM on expansive soil at different locations in Hefei,we know the medium-micro structure of Hefei expansive soil and investigate the influence of microstructure on the physical and mechanical properties. From the study of dry-wet circulation and one-way immersion of expansive soil, we conclusion a series of changes of physical and mechanical parameters. In the end, it comes out the optimum rates of mixing lime in different locations and puts forward some necessary data and reasonable suggestions for the project construction of Hefei through the researches on the improvement by lime on expansive soil.