Research And Application Of "Vertical Three Zones" Distribution Rule Of Overburden Under Multi Coal Seam Hosting Conditions

At present,China is facing the general situation of deep mining.The gas content and gas pressure are bigger and bigger.Coal seam geological conditions are complex,soft coal quality,coal and gas outburst and other dynamic phenomena threaten safety production.The "bottleneck" problem of gas restricted production is also becoming more and more prominent,which can not guarantee the normal production only by air exhaust gas.This paper analyzes the six main factors of overlying strata "vertical three zone" height: nature,rock and mining thick seam working face to face on the length,the advancing speed,coal mining method,using part of mine to take high,high crack statistics,Yang coal mine for test mine,according to the principle of artificial neural network,using MATLAB neural network toolbox Neurel Network Training stopeoverburden "vertical three zone" of the BP neural network prediction model,after repeated retrain effect of overlying strata "vertical three zone" height of the six factors and the "vertical three zone" statistics,training get network training parameters,correlation coefficient All:R=0.91082 of all the data,taking the average relative error is as high as 9.71%;crack the average relative error is as high as 8.50%.The height of the "vertical three band" predicted by BP is close to the statistical data,and the training effect is better.At the same time,the measuring principle and development process of the SF6 tester developed by our company are introduced.By using tracer gas SF6 and segmented water gas liquid two phase composite method,the height of the caving zone of the 8410 working face overlying strata is 21.3m,and the height of the fracture zone is 21.3m~72.6m,the fracture of 45m~56m is more developed.In the last few years,the gas source of the coal mining face of Yangquan coal mine is calculated.The gas emission in the adjacent layer accounts for 89.48%~97.19% of the total amount of gas emission.Analysis and comparison of three adjacent layers of gas control technology,combined with field practice,the use of high pumping roadway to control the adjacent layer of gas.8410 reference field measurement,empirical formula,the prediction of the 8410 working face by using BP neural network training,get the output vector anew=[20.39,71.23],namely the fracture zone height range of 20.39~71.23,in order to optimize the 8410 layers of high drainage roadway layout.The extraction effect of 8410 high pumping alley is investigated and analyzed.The average extraction purity is 35.98m3/min,the average extraction rate is 89.64%,and the extraction effect is stable and good.The gas volume fraction of the back flow of the working face is controlled at 0.36%~0.51%,and the gas volume fraction at the upper corner is never Overlimited,and it is stable at 0.56%~0.75%,good governance results have been achieved.