Research On Acoustic Emission Characteristics Of Coal Mine Rock Under Uniaxial Compression Conditions Of Rock Destruction Process

In this paper, combining the method with the experimental research, theoretical analysis and numerical simulation, the fine-grained sandstone, coarse sandstone and sandy mudstone consists of three groups with different height to diameter rock uniaxial loading failure acoustic emission test process were compared and analyzed and obtained some achievements.First, by uniaxial compression experiments, compared with three groups of rock specimens with different sizes. The basic mechanical parameters would be some change regularly, and in the uniaxial compressive strength would be presented with the increasing size of the enhanced trend, while its deformation modulus, elastic modulus would increase with height to diameter ratio was enhanced, but this trend was not obvious.Then, acoustic emission ringing count with the change of stress strain curve reflected the basic damage deformation of rock specimen. Overall, acoustic emission experiments of three groups of rock specimens were experienced the initial stage of acoustic emission and acoustic emission calm, acoustic emission growth phase, acoustic emission stable stage. As each group of rock specimen size was small, the large number of acoustic emission number ringing before peak had repeatedly appeared significantly. When the size was bigger, the most significant one of acoustic emission events broke out in the peak stress near the number.Acoustic emission energy count feature diagram corresponded with acoustic emission ringing event graph.Under the condition of the same diameter, the higher rock specimen height of each group was, the greater compressive strength was, the smaller transmitted energy was. The damage effect of the rock in the characterization by acoustic emission number ringing would be better.AE source location performance could be used to determine the rock specimen crack extension direction and direction, and to predict fracture surface. And as the change of high with different diameter ratio, three groups of rock specimens showed the same pattern.Finally, using RFPA numerical simulation software simulated the whole test process and got the same results with the experimental process. The results showed that in the case of the same diameter, the greater the height to diameter of rocks were, the greater the uniaxial compressive strength were, the weaker acoustic emission activities were.