Crack Evolution and Mechanical Behavior of Granite with Topological Flaws Under Uniaxial Compression

Fractures with topological characteristics are prevalent in rock masses, influencing their mechanical properties. However, the mechanical properties and crack evolution mechanisms of rock specimens with topological flaws have not been comprehensively studied. This study investigates the mechanical behavior and crack evolution of granite specimens with various topological flaws under uniaxial compression using the digital image correlation method and particle flow code (PFC) simulations. Results reveal that crack initiation, propagation, and coalescence consistently occur at isolated nodes within the topological structure, and the presence of secondary cracks near the main crack's loading end can alter its tensile and shear properties. The peak strength of specimens with different topologies remained relatively consistent, while crack initiation stress decreased with an increasing number of branches. PFC simulations effectively replicate experimental observations, confirming that crack evolution in complex topological structures shares similarities with simpler configurations. Additionally, the peak strength of specimens with complex topology remained relatively consistent, while crack initiation stress decreased with an increasing number of branches. These findings enhance our understanding of the fracture behavior of rock masses with complex fracture networks, crucial for various engineering applications.