| A number of methods have been proposed and used in the prediction ofcoal and gas outbursts. Thought significant advances have been made inunderstanding the mechanism of coal and gas outbursts. There are still someissues on prediction of outburst,in particular,the suitability of outburstprediction indice and their sensitivity to particular seam. In this thesis, gasconten is studied as an index for safe mining against outburst. Laboratory tests,field tests and numerical simulation have been undertaken to useing determinethreshold value of gad content to determine the risk of coal and gas outbursts inthree cola mines at Lu’an Mining.In this thesis, SIMBURST,a numerical simulator,has been used tonumerically determine the outburst threshold value of gas content. SIMBURSTis a three-dimensional numerical calculation program, which is coupled byFLAC3D and COMET3. the gas content is determined with the standard coring method and sum of “lost gas Q1”, Q2and residual gas Q3.The method for the gas content measurements is core coring in the depth of15m,25m,30m,35m,45m,60m in3#seam in Lu’an.A reasonable sampling depthis determine to be30m~35m by error calculation analysis at various samplinglocations in the mine; The basic parameters and boundary conditions of theseam were determined though laboratory and field tests,and used for thenumerical simulation.Useing the coupling of numerical simulation betweenFLAC3D and COMET3, and by increasing the initial gas pressure until theoccurrence of outbursting of coal and gas, the threshold value of the gas contentcan be determined.Results of this study have been applied in3#coal seam of Wuyangmine, Gaohe mine, Gucheng mine at Lu’an. It is determined that the thresholdvalues of gas content against outbursting are8.1m3/t,7.6m3/t,and8.6m3/t forWuyang mine,Gaohe mine,Gucheng mine,respectively.The values have beententatively applied in these mines and the field results have shown to bepromising,indicating the scientific and feasible nature of this method. |
PDF Full Text Request