Experimental study on acoustic emission characteristics of fault slip process based on damage factor

Fault slip is the direct cause of fault-type rock burst in mines, and its process is very complicated. Quartz sand and limestone were selected as the material in this paper, double shear friction experiment was used to study the process of fault slip under different loading rates (0.05,0.075,0.1,0.15,0.2 mm /s) and different horizontal pressures (30,60,90kN), the characteristics of AE of rock sample was obtained under the condition of different loading rates and different horizontal pressures. The results show as follows: The AE energy increases with local stress drops in the process of rock sliding under loading, which shows obvious time synchronization. A damage warning model of fault was established based on the cumulative AE count, and the pre-peak stage was divided into the initial warning stage and the second warning stage by using the time interval prediction method. The results of this study provide a strong experimental basis for the field early warning prediction of fault．