Study On Breeding Characteristics Of Deep Coal And Gas Outburst And The Evolution Law Of Acoustic Emission Energy

Coal and gas outbursts are the most serious dynamic disasters in coal mining.At present,coal mines in my country have entered deep mining.The deep coal is significantly affected by "three heights and one disturbance",which is more likely to induce mine disasters than the shallow ones.The unclear outburst mechanism restricts the reliability and effectiveness of disaster early warning.Therefore,a detailed and quantitative analysis of the whole process of coal and gas outburst incubation and evolution is carried out to systematically understand and describe the whole process and essence of the outburst,combined with the DS5 series of full-information acoustic emission signal analysis and test system and impact force tester,to Liaoning The Sunjiawan outburst coal seam in Fuxin as the research object,The self-developed coal and gas outburst test system was used to carry out physical simulation tests of coal and gas outbursts at different mining depths in deep mines,and the gas pressure and gas pressure during the incubation and evolution of coal and gas outbursts were analyzed.The evolution law of impact force,the characteristics of acoustic emission precursor signals,and the early warning method of acoustic emission parameter trend are adopted in the time series to establish the risk prediction index of coal and gas outburst.The results show that:(1)Coal and gas outburst has three characteristics of "high intensity,fast speed and strong destructiveness".The propagation of impact force in the roadway experienced an evolutionary process of "ascending? peaking ?decreasing".After outburst,the gas pressure in the pressure chamber appeared a phenomenon of "step-down",which verified that the gas pressure in the outburst process was persistent and paroxyminal.(2)Through a critical impact on the prominent characteristic parameter analysis found that the effective stress in the process of outstanding breeding,and in-situ stress play a leading role,deep coal relative to the shallow are more likely to happen,and easier to reach the critical buckling condition,during the excitation-development,gas pressure play a major role,has important influence on coal body thrown.(3)The coal and gas outburst process has gone through four stages: early incubation,late incubation,excitation-development and termination.The acoustic emission energy signals show the "steady?rise?peak" variation in the process of coal and gas outburst.It indicates that coal and gas outburst is a mechanical process of coal damage and energy accumulation.By analyzing the evolution of the various stages of acoustic emission energy,identified precursor signal feature prominent,and the establishment of the risk: average energy E and the number of events predictor of AE coal and gas outburst L.(4)During the evolution process of coal and gas outburst,the stress and damage degree of the coal body in the incubation stage affect the outburst excitation-the impact force propagation continues during the development process and the relative strength of the outburst of the coal body.Therefore,the gas-containing coal body in the outburst incubation stage The mechanical state is related to the outstanding danger.This paper has 49 figures,11 tables and 105 references.