Study On Simulation Experiments Of Coal And Gas Outburst Evolution

Coal and gas outburst is a serious dynamic disaster in mine. In order to controlcoal and gas outburst effectively, domestic and foreign scholars carried out a lot ofresearches on its process and mechanism, however, the understand of mechanism cannot meet the requirements of production. With the intensity and depth of coal miningincrease, problems of outburst become much more severe recent years. In order toreveal the catastrophic mechanism of coal and gas outburst, the paper developed anexperimental system that can simulate coal and gas outburst on different gas pressure,stress and coal conditions. And a mount of experiments were carried on to study theimpact of gas pressure, stress and coal on the outburst. This paper studied the law ofcoal fracture evolution during the process of outburst. It also analysis the law ofelectromagnetic radiation, acoustic emission and potential signal variation.Thecharacteristics of evolution and coupling law, gas pressure,ground stress and coalduring the process of outburst, are studied in this paper, which is verified in the field.The thesis obtained the following main research results.(1) Developed a new experimental system that can simulate coal and gas outburstof different loads, gas pressure, stress, coal conditions and so on. Real-timeobservation of the coal rupture evolution process using a high-speed video cameracould obtain the real-time datum of gas pressure, temperature,electromagneticradiation, acoustic emission and potential during the process of simulation foroutburst.(2) Using this experimental system, a large number of experiments were carriedout, and the coupling relationship among stress, gas and coal was established. Anexperimentally method to determine critical value of coal and gas outburst predictionwas put forward.The formula shows that critical stress of outburst was inverselyproportional to gas pressure. The greater the ground stress is, the smaller the gaspressure required for outburst is. The ability that the coal resistant to outburst isrelative, when the stress and gas as the driving force reach a certain value, hard coalcan also outburst.(3) Real-time observation of the coal and gas outburst process was obtained byusing a high-speed video camera. The law of fracture evolution of coal and itsfractures was studied during the process of evolution for outburst at qualitative andquantitative aspects. The results show that if the gas pressure is greater than0.75MPa, no fracture can be observed in coal and gas outburst process.(4) Multi research methods were used in studying the evolution characteristic andits vary regularities of impact factors during the outburst, such as experimentalmethod, theatrical analysis method and simulation method. An new mechanism ofoutburst named space-time couple unstable was put forward.(5) Analyzed the law of electromagnetic radiation and acoustic emission signalsbefore and after blast. The results showed that electromagnetic radiation and acousticemission were ahead of gas emission, and it can reflect the outburst hazard in front ofroadway better.