Study on Micro Failure Mechanism of Granite under Uniaxial Compression
In order to study the effect of the microstructure and mineral composition of granite on its deformation and failure characteristics in Shuangjiangkou Hydropower Station,uniaxial compression test of granite is carried out to analyze the characteristic stress,characteristic strain and failure form of granite,and the fracture mechanism is analyzed by SEM scanning.The microstructure of granite is simulated by Voronoi polygon,and the uniaxial compression failure process is simulated by discrete elements of block.The mechanical parameters of granite mineral contact are obtained based on orthogonal design-numerical simulation-neural network-intelligent inversion method.The results show that the failure mode of granite under uniaxial compression test is tensile-shear compound failure,and the main fracture angle is 60°~70°.The intergranular failure main-ly occurs in the contact between quartz and plagioclase.The normal stiffness,tangential stiffness and cohesion of the contact between quartz and plagioclase significantly affect the macroscopic mechanical indexes of granite.The fracture morphology and macroscopic mechanical parameters of granite obtained by numerical test and laboratory test are basically consistent,which proves the rationality of using neural network inversion to i-dentify micromechanical parameters,and broadens the application prospect of micromechanical tests.