Analysis Of Influencing Factors Of Coal And Gas Outburst And Microseism Precusor

Coal and gas outburst is common mine disaster, its sudden character and destruction character are extremely strong. The prevention and control to gas burst have already become a worldwide difficult problem. There exists a phenomenon of different kinds of understanding on the mechanism of gas, and there exists bigger bifurcation of understanding on the effect which gas and ground stress take in the gas outburst. On the aspect of monitoring and forecasting of gas outburst, the traditional forecasting method is of some hysteretic nature. So this paper bases on the basic understanding that the micro failure is the coal, gas outburst and etc. mine power disaster precursor characteristic, the break the traditional thought which forecast the mine power disaster according to the gas concentration etc. representation information, start from the essence which geology and environment deterioration progression catastrophe which the mining disturbance induces lead to the happening of mine power disaster. By means of numerical calculation and microseismic monitoring technique and on the basis of gas-solid coupling theoretical analysis in the progress of geology and environment deterioration, summarize and analyze the coal and gas outburst, etc. mine power disaster mechanism, reveal inherent motivation and precursory rule of coal and gas outburst, establish theoretical foundation for real-time forecasting of coal and gas outburst. The happening of gas outburst disaster can be prevented effectively by establish microseismic monitoring system of coal and gas outburst, play a demonstration role in application of microseismic monitoring technique in gas outburst monitoring. The main research content of this present paper is as follows:(1) The micro structure of coal, such as nonuniformity, permeability and the influence which the gas outburst on the randomness of units in numerical simulation are studied. The understanding of gas outburst mechanism and gas outburst phenomenon diversification is strengthened. (2) On the basis of coal physical and mechanical properties nonuniformity, coal and gas intercoupling effect and gas outburst comprehensive supposition, numerical simulation research in the effect of three factors of gas outburst(gas, physical property and ground stress) in gas outburst is done, effect of three factors of gas outburst in gas outburst is qualitatively described, theoretical evidence for cognition of gas outburst mechanism and gas outburst prevention is provided. Meanwhile, according to the research results, an scientific explanation to some gas outburst phenomena is made.(3) The distribution characteristics of microseism in time and space and in the failure progress of gassy coal under different confining pressure is analyzed, effective microseism information and effective prediction method is found , on the basis of this, the distribution characteristics of microseism in coal failure progress of different coal quality and different gas content are analyzed, potential failure risk region according to prediction method which is put forward before is forecast, accuracy of forecast according to coal sample failure law is judged.By using RFPA^3D code study the distribution characteristics of microseism in time and space in the rock-like material three-point bending failure progress, the relation between microseism incidents and stress distribution from the three-dimensional space perspective is analyzed.(4) The influence which soft stratification thickness imposes on the distribution characteristics of gas outburst microseism precursor in time and space is studied, microseism precursor mode when gas outburst happens in soft stratification coal seam is determined. Gas outburst microseism precursor mode which is in the situation of structuring coal across region and fault in the coal seam are analyzed. By comparing and analyzing the microseism precursor incident distribution scale in space and gas outburst law, the accuracy and reliability of forecast methods and results are judged.(5) Gas outburst microseism monitoring system in Xinzhuangzi Coal Mine is established, microseism source waveform library is established, the accuracy of microseism monitoring according to mining situation is analyzed, long-distance transmission of data by network is realized.