Study On The Technology Of Weakening Water Injection To Prevent Erosion In Subarea Of Fully Mechanized Caving Coal Seam In Jinchuan Coal Mine

Xinjiang is the 14th large-scale coal development base in China,and coal is one of the three dominant resources in Xinjiang.Because the coal seam in Xinjiang area is affected by the residual tectonic stress of Tianshan Mountain,a special high stress mining environment is formed.Impact disaster has been a natural disaster in coal mining activities in Xinjiang.Therefore,this paper takes Xinjiang two typical high stress coal mine as the background,using statistical analysis,laboratory experiment,theoretical calculation,field test and engineering practice,the research of water coupling for coal seepage characteristics and stone weakening mechanism,a systematic analysis of the thick coal seam fully mechanized caving face the impact of Ground Pressure Regularity and influence factors,put forward on the basis of stress of coal seam water injection technology difference design method,establish hydraulic coupling seam partition weakening blanking system.And carried on the field engineering application.The study concluded that:Under the influence of hydraulic coupling,the relationship between strain and permeability and stress-strain in high stress coal seam,the relationship between the fracture field and seepage field of coal and the propagation and penetration rule of pore fissure in coal body under the action of mining stress disturbance.The coupling of water pressure in porous fractured coal seams not only provides a path for fluid seepage,but also directly influences and weakens the mechanical properties of coal bodies.Through the analysis of microseismic monitoring,the relationship between the water injection process and the impact performance of the coal seam is studied,and the factors affecting the support resistance and water injection parameters are analyzed.The results show that the weakening water injection into coal seam zone will increase the number and development degree of fracture pores in coal seam and increase the water injection rate in coal seam,which will play the role of wetting,softening the coal seam and reducing the strength.Based on the typical conditions in xinjiang,the industrial experimental study on the water injection technology of the system is carried out.The monitoring of the working resistance of the fully mechanized mining supports shows that the high energy frequency of the roof is obviously decreased and the roof fracture is timely.In the test section,the working resistance of the support is balanced and there is no impact accident.The application shows that the water injection weakening technology of coal seam has important meaning and function to prevent the impact pressure of coal caving face support and reduce the dust concentration of working face.