Experimental Study on Direct Shear Strength of Residual Soil

The physical parameters experiment and indoor direct shear test of residual soil were conducted.The direct shear characteristics of undisturbed soil and compacted soil under different water conditions were analyzed.Results showed that the cohesion and internal friction angle of saturated soil were lower than that of moisture soil,as well as shear strength lower than those in moisture conditions.Under different soil conditions,the reduction ranges of shear strength from the moisture to saturated condition are different.The possibilities of shallow slide and deep slide of slope can be roughly determined by using sensitivity between soil and moisture content.The shear strength of compacted soil is increase to a certain peak value with increased moisture content firstly,and then decreased with the moisture content rising gradually.The curve shows a single peak shape,and this specific moisture content is approach to the optimum moisture content.