Experimental exploration of damage propagation in rocks using acoustic emission

The formation of geological disasters, such as earthquakes and rock bursts, is a process similar to avalanches. These sudden disasters are closely related to a series of discontinuous cracks. In this study, the relationship between the damage process and the jerk phenomenon (sharp change in stress during loading) of rocks was revealed by evaluating the acoustic emission (AE) characteristics of sandstone under triaxial compression. The results show that most of the AE signals during the loading process were low-energy tensile signals. The aggregation and transfer of these low-energy signals could induce jerks. The proportion of high-energy shear signals was very low; however, the high-energy shear signals could induce the jerk phenomenon. Sandstone failure is a process of local failure and stress concentration transfer within the rock. The forms of gather and transfer are different at each loading step. Overall, the transfer law indicates that the damage area disperses to the edge of the sample and then concentrates to the center. The stress transfer and local damage of rocks are accompanied by a series of jerks. This study provides a better understanding of the rock failure process and provides theoretical support for the prevention and early warning of geological disasters.