Study on the self-initiated catastrophe mechanism of strain rockburst: A laboratory experiment

Throughout the full evolution process of rockburst, the instantaneous self-initiated static-dynamic transition behavior represents a pivotal inflection point that propels rocks from static deformation to dynamic instability. Nevertheless, the transient dynamic process of this point and its role in triggering rockburst remain incompletely understood. Addressing the scientific issue, this study proposes a physical simulation methodology to reproduce self-initiated rockburst based on the theoretical framework of rock mechanics systems. Concurrently, a millisecond-resolution multi-source information monitoring system was developed to capture the transient dynamic behavior. Based on such method, controlled experiments were conducted to decode the instantaneous static-dynamic transition process, investigating the self-initiated catastrophe mechanism from mechanical and energy perspectives. Under the work, some new insights into rockburst mechanism are acquired. The results show that: during the transition instant, the surrounding rock within the rockburst system exhibits self-initiated elastic rebound dynamic behaviour that is the key to triggering rockburst. Mechanically, this behaviour directly generates immediate impact loading on the burst rock, performing as the direct cause of rockburst; Energetically, elastic rebound compels the surrounding rock to perform transient work on the burst rock, forming energy convergence and shortening the time required for instability, causing a sufficient large energy release rate within the burst rock, functioning as the inherent cause of rockburst.