Study On The Technical Research Of Cutting And Unloading The Roof Pressure To Protrct The Roadway In ChangCun Coal Mine

China is rich in coal resources,but as a primary energy source,coal itself is not renewable,so the coal recovery rate should be increased as much as possible during coal mining.Mining alleys average service life is longer,bear the entire mining area transport many of the functions,such as material,pedestrians LuAn group Chang Village coal mine in order to maintain stable alleys,decrease the alleys maintenance costs,generally this ahead of the working face 70 m stops coal pillar mining line.Practice shows that 70 m width of coal pillar under the alleys are still affected by mining,also caused the waste of coal resources at the same time,in order to solve this problem the paper in the engineering background of S6-8 Chang Village coal mine working face,cut through the roof pressure relief way to shorten the stop line size of coal pillar,improve resources stoping rate,at the same time make the alleys easy to maintain,and at the same time using the theoretical analysis,laboratory experiments,methods of numerical simulation and engineering practice for further verification,research results for reasonable location of line stop mining under similar conditions of optimization and alleys maintenance to provide certain reference and guidance.The following results were achieved:(1)In the S6-8 Chang Village coal mine working face and the circumstances and collection of data on the basis of the method of using peep and physical and mechanical parameters of drilling experiments on the working face roof and floor rock lithology and determine the specific mechanical parameters for further.(2)Calculate the overburden load on the working surface of s6-8,determine the position of key strata,and provide theoretical basis for the stability analysis of coal pillar in stop-mining line;The stability of coal pillar in stop-mining line is generally affected by the buried depth of working face,the lithology of coal rock mass,the dynamic pressure of working face,the shape of the roadway protected by coal pillar,the service life and the supporting method.For S6-8 Chang Village coal mine working face advancing scope of abutment pressure theory calculation,theory under the condition of ore Chang Village S6-8 line face stop mining coal pillar width is 70 m alleys when affected by abutment pressure is not big,easy maintenance of roadway,and the mine actual consistent and stops coal pillar mining line width.(3)Combined with FLAC3 D numerical simulation software,the feasibility of roof unloading pressure retaining roadway is verified.The simulation shows that the larger the width of coal pillar is,the higher the stability of roadway is.The deformation of surrounding rock of material inclined roadway decreases in different degrees under the condition of cutting top,which indicates that the technology of cutting top unloading pressure protecting roadway can shorten the size of coal pillar of stop-mining line and make the roadway easy to maintain.(4)On the basis of the study of blasting damage mechanism according to actual situation field implementation plan,in S6-8 face material in inclined lane parallel arrangement of 11,21.6 m long hole to cut the top pressure relief roadway protection scheme design and industrial test.(5)Field measurement of lead bearing pressure indicates that the influence range of lead bearing pressure on working face of s6-8 is about 72 m,indicating that the roadway in the mining area is actually affected by working face mining.Material inclined lane at the top of the cutting speed of roadway deformation after unloading significantly decreases,and that cut the top pressure relief to have cut the abutment pressure,reduce the stress of coal pillar roadway maintenance,easy to cut and alleys,top pressure relief can be used in the miningarea and shorten the stop line size of coal pillar,the alleys easy maintenance.