Comprehensive prevention and control research on rockburst in ultradeep shaft based on theoretical deepening and practical verification

With the continuous increase in underground engineering depth, rockburst—a highly destructive geological hazard—poses a significant threat to the safety and stability of engineering projects. This study focuses on the rockburst challenges in the −1915 m ultra-deep shaft project of the Sanshandao Gold Mine, situated 125 m from the active Sanshandao Fault Zone. By integrating theoretical analysis, numerical simulation, and microstrain monitoring, this research systematically explores rockburst mechanisms, prediction models, and support optimization strategies. Through in situ stress measurements, rock mass quality evaluations, and structural plane analyses, the geological conditions and rockburst initiation environments in the study area are systematically characterized. A rockburst prediction model grounded in variation and functional theory incorporates stress tensors, strain energy density, and damage variables to accurately identify the intersections of structural planes in the surrounding rock at the −1561 m shaft depth as high-risk zones. Based on failure mechanisms and support action principles for different rockburst grades, corresponding support schemes are proposed, and support parameters for bolts and linings are meticulously calculated using composite arch theory. Numerical simulations and engineering monitoring confirm that the support schemes applied to rockburst-prone areas effectively reduce the plastic zone radius and control shaft convergence within 0.28 %. Field microstrain monitoring demonstrates that the support system significantly mitigates deformation in the maximum principal stress direction, with surrounding rock deformation stabilizing within 21 days. This study enhances the understanding of rockburst dynamics in ultra-deep shafts and offers a transferable methodology for global deep mining projects.