Study On Multi-index Informatin Fusion Warning Technology Of Rock Burst In Laohutai Coal Mine

Rock burst is one of the main hazards of deep mining. With the increase of mining depth, strength and frequency of rock burst are on the rise, and has become a serious threaten to mine safety and efficient production. The Laohutai coal mine belongs to the typical impact coal mine, and the rock burst accident is frequent. Monitoring rock burst hazard and improving the accuracy of rock burst hazard warning have great practical significance for the safety production of coal mines.In this paper, characteristic and precursor rule of microseism, electromagnetic radiation and acoustic emission of rock burst in main working face(73005 working face, 83003 working face) of Laohutai coal mine in 2014 are analyzed. Then, multi-index information fusion warning technology of rock burst of Laohutai coal mine based on D-S evidence theory is studied and verified. The results show that:(1) Rock burst events in 73005 working face and 83003 working face of Laohutai coal mine are near the fault and mainly focus on high stess area of 30 meter away from working face, and be closely related to advance progress of mining surface. Fault structure, properties of coal and rock, mining depth, mining activities and supporting conditions are mian influencing factors of rock burst occurenced in Laohutai coal mine.(2) Before the rock burst of Laohutai coal mine, microseismic signal has abvious volatility and exist low value in five days advancing. On the whole, the changing tendency contains “rising” type, “V” type and compound type. And the whole changing tendency of electromagnetic radiation and acoustic emission signals contains two main basic types, including “rising” type and “inverted V” type. Comparatively speaking, there are more changing forms for electromagnetic radiation signals. And “inverted V” type is the main expressive form of acoustic emission signals.(3) This paper determines b value of microseism, electromagnetism intensity fluctuation gradient △ E, electromagnetic pulse fluctuation gradient △ N, acoustic emission ringing fluctuation gradient △ R and acoustic emission amplitude fluctuation gradient △ A as the main research indexs of rock burst monitoring and warning and obtaining the threshold as the critical value of judging the hazard level of rock burst.Then, establishing the multi-index information fusion warning system with above indexs as evidence body based on D-S evidence theory, and through verified in 63007 working face. The result shows that there are warning signals before all rock burst events and no omission and the early warning accuracy rate is 85.7 percent.