Experimental investigation on synergetic prediction of granite rockburst using rock failure time and acoustic emission energy

The frequent occurrence of rockburst and the difficulty in predicting were considered in deep engineering and underground engineering. In this work, laboratory experiments on rockburst under true triaxial conditions were carried out with granite samples. Combined with the deformation characteristics of granite, acoustic emission (AE) technology was well applied in revealing the evolution law of micro-cracks in the process of rockburst. Based on the comprehensive analysis of acoustic emission parameters such as impact, ringing and energy, the phased characteristics of crack propagation and damage evolution in granite were obtained, which were consistent with the stages of rock deformation and failure. Subsequently, based on the critical point theory, the accelerated release characteristics of acoustic emission energy during rockburst were analyzed. Based on the damage theory, the damage evolution model of rock under different loading conditions was proposed, and the prediction interval of rock failure time was ascertained concurrently. Finally, regarding damage as an intermediate variable, the synergetic prediction model of rock failure time was constructed. The feasibility and validity of model were verified.