The Research And Experiment Of The Relief Range Of Yang Dong Mine Mining Protective Layer

In recent years,with the depth of coal mining to extend to the deep,geological conditions has become more and more complex,and high gas coal mine became more and more,coal and gas outburst disasters have occurred from time to time,and how to take measures to eliminate coal and gas outburst becomes an important research topic.For coal seams mining,protection layer mining is the most economical and effective measure to eliminate coal and gas outburst at present.However,the most important of protective layer mining is the determination of the discharge pressure range of protective layer mining.Theoretical analysis,field test and numerical simulation are used in this paper,and studied that the Yang Dong mine exploits protective layer of No.4#seal for protected layer of No.2#seam of the pressure relief scope and effect.The results show that:(1)4#Seam as a protective layer mining,reducing 2#seam raw gas pressure,gas content and enhancing seam permeability coefficient has a very effective role.In the scope of protection,the gas pressure is reduced to about 0.5MPa(below the critical value 0.74MPa),and the gas content is reduced to 5.47m3/t(below the critical value 8m3/t).the 2#seam of swelling distortion magnitude is up to 155.0mm,and the maximum expansion rate is up to 25.8 per thousand.(2)4#seam for seam along the lower part of the tilt direction of the pressure relief angle is 76°,and the upper pressure relief angle is 84°,and along the direction of the pressure relief angle is 60°.Yang Dong mine 4#coal seam as protective layer,can effectively eliminate 2#seam coal and gas outburst,And the pressure relief range is determined.The results of this study not only has important practical value to guide the Yang dong mine safety production,but also has a certain reference significance for other coal mines,and can be widely used in domestic coal mine.