Effects of dike interface and initial damage on granite rockburst tendency: insights from elastic energy and acoustic emission
摘要
In deep underground engineering, the synergistic effects of dike interfaces and initial damage significantly influence the brittle-fracture characteristics and rockburst tendency of rock masses. To investigate this phenomenon, a multiscale experimental approach was adopted to characterize the mesostructural evolution of veined granite specimens with varying levels of damage, particularly focusing on the coupled mechanisms governing their brittle-failure behavior and susceptibility to rockbursts. The research results indicate that the presence of rock veins increases the complexity of the pore structure, causing more large pores. The orientations of weak planes differ across the rock-vein interface, mica flake structure, and quartz-particle cementation zone. Granite with rock-vein interface-like characteristics exhibits a staircase increase in the rate of AE energy before reaching its peak value, featuring progressive failure. Specimens with rock veins generate more AE events and show more pronounced characteristics of concentrated energy release. As the initial damage intensifies, the cumulative ring-down count (RDC) and the rate of release of AE energy show a more significant staircase growth, with the values reducing successively, suggesting that initial damage weakens the brittle-failure characteristics of the rock. When the initial damage value