Multi-factor-induced Shear Strength Test Of The Clay In Guangxi Province

Slope deformation and failure is a kind of natural phenomena present in almost all the rivers in the world. Rapid drawdown, torrential rain and atomized rain, ship wave are the main factors that lead to slope deformed or unstable. In different area, due to the different geological conditions, the mechanisms of slope failure caused by different factors are distinct. So, it is necessary to do the slope failure mechanism research. In this paper, for the Guangxi Naji reservoir slope restoration project, using test method, the shear strength of clay slope is studied. The main research work consists of the following parts.(1) For the rapid drawdown case, the triaxial test with seepage is studied by using the SLB-1 stress-strain controlled triaxial shear seepage tester. The parameters of shear strength with seepage are obtained. The shear strength decreases with the seepage pressure increasing. The main reason is that cohesion decreases with the seepage pressure increasing.(2) For the torrential rain case, the shear strength of unsaturated clay in different matric suctions is studied by the triaxial test by using the SLB-1 stress-strain controlled triaxial shear seepage tester and air pressure controller. The parameters of shear strength of unsaturated clay are obtained. Cohesion increases with matric suctions increasing. Angle of internal friction first increases and then decreases with matric suctions increasing.(3) For the ship wave case, the triaxial test of saturated clay under cyclic load is carried out by using the British GDS company's the dynamic triaxial testing system DCSS. After cyclic load, the parameters of shear strength re obtained. The shear strength parameters are reduced than those were not under the cyclic load. And under the same cyclic load, the reduction factor of cohesion is larger than the reduction factor of the angle of internal friction.