Abstract:
Taking the weathered sand situated in the Three Gorges reservoir area as the research object, mixing different amounts of cement with the weathered sand, and then changing the shear rates, changing the overlying vertical load, indoor direct shear tests have been carried out. This study has analyzed the impacts of the shear rates, the vertical load on the shear strength index of the cement-stabilized weathered sand having different cement contents. Experimental analysis results show that the shear rate and the vertical load have a significant effect upon the shear strength index of the cement-stabilized weathered sand. By the same action of the shear rates and the vertical load, the cohesive force of the cement-stabilized weathered sand will significantly increase with increase in the cement content, but the internal friction angle will first become great and then small; when the cement content is the same, increasing the shear rates and the vertical load will significantly increase the cohesive force of the cement-stabilized weathered sand and reduce its internal friction angle. When the shear rates are large, the sample in the process of shear failure not only overcomes the slip among the particles, but also overcomes the rotation of the particles and the transposition rolling resistance to increase the cohesive force. Larger vertical load will make the specimen have greater compression consolidation, reduce intergranular porosity, increase the water stress and the vertical additional stress within pores, and finally enhance the intergranular interaction force as well as the shear strength of the weathered sand.