Analysis of Stress-strain and Shear Strength of Unloading Soil in Pit Excavation

According to the lateral unloading stress path in pit excavation,the ordinary and true triaxial consolidation shear tests are completed under the drainage conditions by choosing the representative silty clay in Wuhan City.The deformation and strength characteristics of silty soil in the lateral unloading condition are obtained,which includes the relationships between stress and strain,the axial strain and horizontal strain,the axial strain and volumetric strain.At the same time,the strength change rule of tested soil is discussed and the parameters of unloading soil are gained.The test results show that the characteristics of soil deformation are different in different stress states under the same stress conditions.Therefore,it must take different design methods and support systems for actual excavation projects based on the true force states of unloading soil.