Issue 36

S.R. Wang et alii, Frattura ed Integrità Strutturale, 36 (2016) 182-190; DOI: 10.3221/IGF-ESIS.36.18 182 Acoustic emission characteristics of instability process of a rock plate under concentrated loading S.R. Wang Opening Project of Key Laboratory of Deep Mine Construction, Henan Polytechnic University, Jiaozuo 454003, P.R China w_sr88@163.com C.Y. Li School of Civil Engineering, Henan Polytechnic University, Jiaozuo 454003, P.R China Z.S. Zou , X.L. Liu Opening Project of Key Laboratory of Deep Mine Construction, Henan Polytechnic University, Jiaozuo 454003, P.R China A BSTRACT . It can facilitate the understanding of the mechanical properties and failure laws of rocks to research on the rock failure mechanism and evolution characteristics of Acoustic Emission (AE). Under the concentrated loading condition, the fracture and instability test of a rock plate was conducted by using the rock Mechanics Testing System (MTS), meanwhile, these AE events were recorded through the AE recording system. Based on the laboratory test, the numerical simulation was completed by using FLAC 3D technique under the criterion that the rupture of a cell or several adjacent cells was regarded as an AE event. The results show that the process of the fracture and instability of the rock plate can be divided into four stages, such as the stress adjusting stage, the brittle fracture stage, the rock-arch bearing load stage and the rock-arch instability stage. And the acoustic emissions display the different characteristics in each one of the four stages. The temporal and spatial distribution characteristics of the AE events with large magnitudes are very similar to those of the natural earthquakes. K EYWORDS . Rock mechanics; Rock plate; Acoustic emission; Numerical simulation; Instability. I NTRODUCTION ince rock failure is always accompanied by Acoustic Emission (AE) phenomenon, it can facilitate the understanding of the mechanical properties and failure laws of rocks to research on the rock failure mechanism and evolution characteristics of acoustic emission. Currently, the study methods of AE mainly contain the means of laboratory test or numerical simulation or both of them. In the experimental research field, both domestic and foreign scholars have conducted plenty of studies. For example, S.L. Li, et al. investigated the rock mechanics and AE characteristics in the whole failure process for rock samples and pointed out the test results could be used to explain the AE phenomenon in an engineering project [1]. X.M. Fu compared the similarities and differences of these AE performances for different rocks in the uniaxial compression tests [2]. Based on the locations of AE events, X.D. Zhao, et al. found that the AE distribution could reflect the shape and development of S