Time-Delayed Rockburst: Investigating the Mechanism of Fracture Initiation

Confirmation seminar presented by Tengzhou Wang.

Time-delayed rockbursts, which typically exhibit six days to months post-excavation, pose a significant hazard in deep tunneling. However, understanding of the occurrence mechanism of this type of rockburst remains lacking. To investigate the underlying mechanisms of time-delayed rockbursts in deep tunnels, this study focuses on the role of rock crack initiation (CI) threshold as a key factor in understanding these events. CI not only reflects the in-situ spalling strength but also delineates the lower boundary of long-term rock strength. Through laboratory experiments that simulate stress conditions in deep tunnels over time via cyclic and creep loading, this research exposes the stress-related triggers of time-delayed rockbursts. The findings aim to solidify the predictive models, offering a proactive approach to understanding and mitigating these complex geological phenomena.