Rockburst criterion for deep-buried tunnels based on rock integrity failure criterion

Rockburst is one of the critical scientific challenges demanding urgent resolution in deep mineral resource exploitation and underground engineering construction. Based on elastic strain energy and the rock integrity failure criterion, combined with the secondary stress distribution of surrounding rock after deep-buried tunnel excavation, this study establishes a multi-factor integrated criterion model for evaluating rockburst propensity. Results demonstrate that the proposed criterion systematically synthesizes key parameters including rock mass tangential and radial stresses, rock integrity, Poisson’s ratio characteristics, and secondary stress redistribution effects, while specifically integrating three essential factors governing rockburst initiation: stress concentration state, structural integrity condition, and material brittleness property. Based on the intensity variation of rockburst activity, the classification system is established with four distinct grades: none, weak, moderate, and Strong, with three classification thresholds determined at 2.5, 8.1, and 25.7, respectively. The sensitivity characteristics of each parameter were also discussed. The results show that the ratio of tangential stress to compressive strength of the rock mass has the greatest influence on the classification of rockburst intensity. When this ratio exceeds 0.75, Strong rockburst is more likely to occur; when it approaches 0.40, moderate rockburst is more likely to occur. Empirical investigations incorporating case studies of representative deep tunnel projects across China demonstrate that the criterion’s predictive outcomes exhibit strong alignment with actual rockburst manifestations while maintaining robust consistency with classical rockburst criteria, thereby demonstrating enhanced predictive accuracy and broad applicability. The developed energy-stress synergistic rockburst criterion offers an innovative methodology for strain-type rockburst prediction in deep tunneling engineering.