Study And Application On Support Technology Of Fully Mechanized Coal Mining Gateway In Extremely Thick And Soft Coal Seam

Through theoretical analysis, laboratory experiment, numerical simulation and field testing methods, support technology of fully mechanized coal mining gateway in extremely thick and soft coal seam is studied. Based on the theory analysis, influence factors on surrounding rock stability of roadway, bolt support mechanism and bolt effective support conditions are studied. Through rock mechanics test, physical and mechanical parameters of coal and rock are got, through secondary stress monitoring, vertical stress change law on the top of roadway is obtained. Based on extrusion reinforcing arch and non-elastic area theory, the roadway support is designed and three support schemes are put forward.Designing a new kind of bolt that is high strength metal thick tail yieldable bolt. Using FLAC3D software, stress field evolution and change law of surrounding rock of roadway of each scheme during roadway excavation and working face advance process are simulated, and preliminary support scheme is determined. Through surrounding rock distortion during field industrial test and measurement, support scheme parameters are changed, and the last scheme of "high strength metal thick tail yieldable bolt+'W' metal strip+wire netting+anchor cable" is determined. Through analysis of economic and social benefits, the last support scheme is proved economic and reasonable.