Prediction and critical transition mechanism for granite fracture: Insights from critical slowing down theory

Rock fracture warning is one of the significant challenges in rock mechanics. Many true triaxial and synchronous acoustic emission (AE) tests were conducted on granite samples. The investigation focused on the characteristics of AE signals preceding granite fracture, based on the critical slowing down (CSD) theory. The granite undergoes a transition from the stable phase to the fracture phase and exhibits a clear CSD phenomenon, characterized by a pronounced increase in variance and autocorrelation coefficient. The variance mutation points were found to be more identifiable and suitable as the primary criterion for predicting precursor information related to granite fracture, compared to the autocorrelation coefficient. It is noteworthy to emphasize that the CSD factor holds greater potential in elucidating the underlying mechanisms responsible for the critical transition of granite fracture, in comparison to the AE timing parameters. Furthermore, a novel multi-parameter collaborative prediction method for rock fracture was developed by comprehensively analyzing predictive information, including abnormal variation modes and the CSD factor of AE characteristic parameters. This method enhances the understanding and prediction of rock fracture-related geohazards.