Rockmass is a complex elastoplastic geological body. Under external loads, macroscopic failure is produced through cracks within a variety of micro-crack formations. In the process of rockmass instability, it is accompanied with crystal disloca-tion, crystals slip, elastoplastic deformation, crack initiation, and propagation until instability occurs. Simultaneously, energy is released in the form of stress waves. Stress wave techniques, such as acoustic emission (AE) and microseismic (MS) monitoring, have been used for many decades to study the fracturing behavior of rocky materials. AE uses transient waves emitted by the initiation and propagation of cracks when a material is under stress [1]. In the 1930s, Obert and Duvall discovered AE event activity from the internal structure of rock under pressure; explosive AE events were monitored in the Amick copper mine in 1940 to predict the advent of rockburst [2]. This phenomenon shows that the physical and mechanical properties of rock material itself are closely related to the loading process and mechanism. AE phenomena vary with the nature of the rock material and loading methods. Regarding AE activity rate characteristics throughout the entire process of rock failure, several researchers have focused on rock compression, tension, shear and fracture testing [3-7]. These researchers intensively studied the relationship between stress, strain, and AE parameters before rock peak intensity. Several studies reported the characteristics of the relatively quiet period of AE before rock failure [8-10]. The characteristics of MS events activity rate and b-value change of rockmass instability was successfully obtained through 6 stope collapses in deep mining [11].
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