Study on the Constitutive Model and the Identification of Parameters of Granite Based on the Crack Closure Ratio

Abstract

A large number of cracks exist inside brittle rocks, and the evolution and expansion of cracks inside rocks have adverse effects on the deformation and strength of rocks, leading to the reduction of mechanical properties of rocks and endangering the stability and safety of rock engineering. Taking the granite samples taken from underground plant of Yebatan hydropower station as the research object, conventional triaxial compression tests were carried out. The characteristics of crack evolution and expansion in granite is investigated, and the parameters of granite are analysed and identified for different mechanical states by using stress-crack strain evolution constitutive model. The stress-crack strain evolution constitutive model was embedded into FLAC3D for triaxial loading tests through secondary development. The results show that the stress-crack strain evolution constitutive model is reasonable and accurate enough to be applied in numerical simulation of underground power-house of Yebatan hydropower station.