Study On The Outburst Prediction Sensitive Index For The Driving Face Of Coal Roadway Of Baiyangling Coal Mine

Coal and gas outburst is one of the natural disasters which threat of coal minesafety production seriously, outburst prediction is the first link in the comprehensivemeasures named "quaternity" for preventing gas outburst using. and the outburstprediction for the driving face of coal roadway is the key point. For different miningarea have different coal seam hosting, geological, gas and physical mechanicscharacter of coal, each kind of prediction index using for coal roadway excavation hasdifferent sensitivity and critical value in different mining areas and seams.Baiyangling coal mine is coal and gas outburst mine, main No.15mineable coal seamis outburst coal seam. In the digging process of the first mining15101face’s coalroadway, the outburst prediction index measured values exceeded frequently, result inhuge amount of outburst-prevention project, slow pace of coal roadway excavation,the conflict of exploitation and mining. In order to improve accuracy andeffectiveness of the outburst prediction of this coal roadway excavation. This paperinvestigates both the selection of outburst sensitivity index and the determination ofits critical value.This paper investigates both the regional tectonic evolution and the geologystructure characteristic, analysis of embedding depth of coal seam, bedrock depth,roof and floor litho logic, floor level and hydrogeology condition on the occurrence ofcoal seam gas, come to both the embedding depth of coal seam and the depth of roofand floor mudstone are the main controlling factors of coal seam gas content in thisarea, and establishing mathematical model, prediction of deep coal seam gas contentdistribution; Based on grey system theory, select the coal seam gas content as thegenerating factor, methane desorption index of drilling cuttings Δh₂, K₁and drillingsvolume S as the sub-factors. studying of these indexes based on grey correlationanalysis, showing the integrated incidence degree of both the K₁and the generatingfactor is biggest, K₁can be defined as sensitivity index; On this basis, tracking theprocess of coal roadway excavation, synchronous test of both the K₁and the coalseam gas content, the data of regression analysis showing that the two factors haveexponential relationship, according to the above the individual provisional critical value of the K₁is0.56ml/(g min^0.5)（The corresponding coal seam gas content is8m³/t）, finally, using the "for rates method" for the site validation, results showing thatthe selected critical value is reasonable.