3D Visualization and Quantitative Characterization of Granite Damage under True Triaxial Stress Conditions

Damage caused by disturbances in deep rockmass is a key factor triggering seismic hazards such as rockbursts. In this study, triaxial loading and acoustic emission (AE) tests were conducted on granite, and the response characteristics of AE during the granite failure process were analyzed. To better characterize the cumulative damage effects of rock crack expansion, the concept of the AE spatial-accumulated energy release coefficient (AE SAERC) was introduced. A 3D Kriging interpolation method was employed to visualize and quantify the extent of rock damage. The results showed that the ordinary Kriging 3D interpolation algorithm, based on a spherical model, provided optimal performance in visualizing rock damage. It effectively demonstrated the evolution of various damage zones in granite during progressive failure. Low, moderate, and high damage zones progressed in stages throughout the failure process, in an irreversible manner. The distribution of high damage areas closely aligned with the internal fracture zones of the rock, further validating the accuracy of the 3D visualization algorithm. Additionally, this study analyzed the volume proportions of undamaged, mildly damaged, moderately damaged, and highly damaged zones. A combination weighting method, integrating the Analytic Hierarchy Process and the Entropy Weight Method, was used to define the 3D rock damage factor. This process enabled quantitative characterization of rock at various stages of damage. This study not only enhances the theoretical framework of rock damage but also offers new insights for monitoring rock mass stability and disaster early warning in underground engineering.