Study On Disaster Inducing Factors And Mechanism Of Impact Rock Burst In Extra Thick Coal Seam In Fold Structural Area

With the shifting of the focus of coal mining to northwest in China,Huating Mining Area is an important coal resource in Northwest China,and the main coal seam in Huating Mining Area is extremely thick coal seam in folded structure area,which is under threat of rock pressure disaster during mining.It can be seen from previous studies that the impact ground pressure in the structural area is the result of mining activities in the geological structural area.Particularly typical for Extra-thick Coal Seam in fold structure area,mine quake occurs due to high-level stress of fold structure and mining activities,thus increasing the risk of rock burst.This paper takes Extra-thick Coal Seam in fold structure area of Huating Mining Area as the research object,and combines the methods of statistical analysis,quantitative analysis,numerical simulation,theoretical analysis and field practice to carry out the research.The main control factors and scouring mechanism of rock burst during mining in Extra-thick Coal Seam in fold structure area are studied.The occurrence regularity of mine quake during mining at typical working face and the characteristics of typical working face are counted,the main influencing factors affecting mine quake are obtained,and the obvious characteristics during mining of Extra-thick Coal Seam in folded structural area are obtained.The main influencing factors of impact ground pressure in Huating Mining Area are analyzed,and a weighting quantitative analysis system of impact ground pressure influencing factors on typical working face of Extra-thick Coal Seam in fold structure area is established based on analytic hierarchy process,and the main controlling factors of impact ground pressure during mining of Extra-thick Coal Seam in fold structure area are obtained.Based on the analysis of characteristics of energy storage in thick coal seam,under the same stress state of surrounding rock,the relationship between elastic energy stored in coal and rock mass and thickness of coal seam as well as the relationship between advanced support stress in coal seam mining and lateral support stress and thickness of coal seam is discussed.Based on geological conditions of 5 seams roof and floor in Huating Coal Mine2501 and Yanbei Coal Mine 2502,FLAC3 D numerical model is established to analyze the change characteristics of fold structure on original stress of coal seam,and the influence of vertical stress of "roof-coal seam-bottom coal" on working face during mining of Extra-thick Coal Seam in fold structure area is analyzed,so as to obtain extrathick coal seam worker in fold structure area.Risk identification of impact ground pressure corresponding to different areas during working face mining.Statistical statistics of technical measures for prevention and control adopted during mining of extra-thick coal seam working face in folded structure area of Huating Mining Area and analysis of pressure relief effect are made,optimization of drilling parameters for floor borehole relief under high stress state of bottom coal is put forward,and parameters for coal body and new roof technology to be adopted are proposed;different optimum layout parameters of prevention and control measures for "top-coal seam-bottom coal" are put forward as well.Arrangement parameters of the new technology in the prevention and application of impact ground pressure.This thesis has 71 figures,18 tables and 92 references.