Characterization of Fracture Propagation in Granite under Uniaxial Compression Test through Digital Image Processing and Discrete Element Method

This study utilized digital image processing (DIP) and discrete element method (DEM) to explore the correlation between mineralogy and fracture propagation in granite. The study concludes that an increase in the content of quartz and feldspar leads to a gradual increase in the uniaxial compressive strength (UCS) value of granite. However, the UCS value of granite undergoes a significant decline with increasing mica content. Additionally, the presence of quartz intensifies the brittleness of granite, while feldspar enhances the ductility of granite. In the isotropic model, fractures tend to initiate from stress concentration points and propagate during the UCS test, causing further stress concentration due to the creation of high-stress zones by the crack tip. In the anisotropic model, fractures usually occur in areas where quartz and feldspar are more concentrated because of a higher likelihood of stress concentration in those regions. However, mica agglomerations are not susceptible to stress concentrations due to their low strength and high toughness, which serve as a buffer.