Test On Breakage Behavior Of Weathered Granite Rock And Mechanism Interpretation With Microstructure Variation Numerical Simulation

Granite is widely distributed in south China, influenced by the humid and rainy climateof Subtropical regions, it would be weathered in different degrees. This article selects graniteof different weathering degrees from conghua Guangzhou, based on the research method ofmesoscopic mechanics,to study the mechanism of deformation and failure mechanism. Basedon numerical simulation incorporating with experimental tests, the mechanical behaviors ofgranite of different weathering degrees are studied from meso-scale to macro-scale,considereing the deformation, damage and nonlinear fracture behavior. Thus, a meso-scalediscrete element model for studying the fracture behavior of rock is presented; meanwhile, amultiscale method for bridging the relationship between mesoscopic and macroscopic levelare presented, laying a foundation for further study of damge and fracture mechanism ofheterogeneous and quasi-brittle materials. The study includes:(1) Damage behaviors of weathering granite are studied by the Brazilian splitting anduniaxial compression test, to figure out the strength and Deformation and failure rules ofgranite of different weathering degrees.(2) Based on digital image processing technology, and mineral components identificationresults of granite by with electron microscope scanning test, a discrete element model isestablished to describe the rock structure of granite. Based on the presented model, hesplitting tensile tests of granite are performed by numerical simulation, the influences bymesoscopic structure, central Angle and end friction are studied. Comparing numericalsimulations with experimental tests, the reliability of the model is certificated.(3) Based on the images of specimen cross sections of weathering granite, numericalsimulation specimens corresponding with the sections are generate, the strength and behaviorof breakage of weathered granite are studied by numerical simulation.(4) By introducing the spatial correlation random field to describe the rock stucture, thenumerical distribution of spatial correlation random field is generated. A correspondingmesoscopic discrete element model is generated by introducing the numerical distributioninto particle discrete element program PFC.(5) Base on the mesoscopic discrete element model with spatial correlation randomfield, the numerical Brazilian test and uniaxial compression test of weathering granite areconducted. Comparing numerical simulations with experimental tests, the reliability of themodel is certificated.