Understanding the mechanisms and mitigation strategies for disturbance-induced rockbursts is essential for ensuring safety in deep rock engineering. To evaluate the effectiveness of drilling pressure relief, uniaxial compression tests were conducted on high-stress, cavity-containing sandstone under low-frequency disturbance loading at various amplitudes. Progressive damage was monitored using acoustic emission and digital image correlation. The threshold disturbance amplitude required to trigger dynamic failure was 25% of uniaxial compressive strength, which was significantly higher than that of intact sandstone. During the stable-damage stage, damage accumulated primarily through small-scale tensile fracturing, whereas large-scale shear fractures developed at later stages, initiating and propagating macrocracks that signalled impending structural instability. The energy-storage limit of cavity-containing sandstone was found to be independent of the loading path. The input energy during disturbance was stored as elastic strain energy and rapidly exceeded its storage limit, thereby driving crack propagation and rockburst failure. An energy pre-release ratio (EPR) was introduced to quantify the premature release of elastic strain energy induced by cavity instability. For all disturbance amplitudes, the EPR exceeded 45%, demonstrating that the cavity effectively mitigates disturbance-induced rockbursts. The results of this study provide a theoretical basis for evaluating the effectiveness of drilling pressure relief in mitigating disturbance-induced rockbursts.
Feng et al. (Sun,) studied this question.