| Failure of rock mass forcasting by acoustic emission (AE) technology is the future direction of mine safety monitoring and non-contact monitoring and predicting techniques. AE technology can be used for the in-situ stress test and dynamic detection for solid materials, equipment and structures. At present, the research on AE characteristics of backfill is little; in addition, backfill mining method is leading mining method of underground mining in the future. Therefore, emphasizing the research on AE characteristics of backfill and establishing a reasonable criterion of failure are urgent. The thesis based on the statistical analysis of status on the application of AE technique in mines, with experiments, then analyzed AE characteristics during the process by fractal theory, AE relative strength-weakness criterion and long-term correlation, to take in-depth research.The main contents and conclusions are as follows:(1) AE Experiments of cemented tailings fill under uniaxial compression were carried out and studied on the characteristics of deformation,uniaxial compressive strength of samples and the distribution of AE. The results show that the characteristics are greatly influenced by the ratio of samples and loading rate; and it confirms that the variations of AE rate and energy rate are synchronous.(2) AE test datas were analyzed by the above mentioned three theories,we not only obtained the variation of the analysis parameters, but also evaluated the effect of three methods,among them, the long-range correlation theory is the best,the establishment of a reasonable criterion is based on the above research.(3)It focused on the loading rate effects on AE characteristics of the samples, and summarized on the variation of basic parameters of the AE (AE rate and energy rate) changing with the loading rate. Finally, it created 2-D crack growth model based on fracture mechanics, and deduced the origin of acoustic emission which generated within the structure. |
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