Research On Overburden Movement And Failure Law Of Full-mechanized Top-caving Mining Of Chenjiagou Coal Mine

Fully-mechanized top-coal caving mining has become one of the widely used miningmethod in thick coal seam in China, but due to the once mining and caving height is large, theoverburden failure caused by this mining method is very serious, the water flowing fracturedzone is of development, the surface subsidence is violent, the surface destruction is serious,and the ground fissures are also of development; Further, when the ground fissurescommunicate with water flowing fractured zone, it will seriously jeopardize mine safety inproduction, and the collapse failure that caused by coal mining will seriously damage theecological environment of mining area as well. Currently there are less research on overburdenfailure law of fully-mechanized top-coal caving mining at home and abroad, the measured dataand engineering cases for reference are also few. So, it is of great theoretical significance andpractical value to carry out systematic research on overburden movement and failure law offully-mechanized top-coal caving mining in thick coal seam.In this thesis, the research object is fully-mechanized top-coal caving mining in extremelythick coal seam in the Third mining area of Chenjiagou Coal Mine in Huating Mining Areaunder Beirui River, also, the author has analyzed the Chenjiagou Coal geology and miningconditions, the lithology, structure, physical and mechanical characteristics, aquosity andimpermeability of overburden above mining coal seam, and the main factors that control thedistribution law of water flowing fractured zone. Measuring the leakage of injection water inthe upward slant hole is employed to detect the development height of water flowing fracturedzone in the3201/3202Face. The detection results show that overburden failure caused by thefully-mechanized top-coal caving mining in extremely thick coal seam is far more violent thanthat aroused by any other mining methods; In addition, there are lots of separated strata spacein water flowing fractured zone, and the ratio of the height of the water flowing fractured zoneto the mining height is12.22. Based on the analysis of detection results underground, combined with the numerical simulation calculation, the maximum height and distributionform of water flowing fractured zone are provided. According to the detection results on thedepth of corresponding ground fissures of the third mining areas, this thesis has analyzed andgiven the calculation formulas on the thickness of waterproof coal (rock) pillar for safetymining of Chenjiagou Coal Mine under Beirui River,and test mining in the3203Face of theThird mining area is conducted as well; The test mining results show that the mining of the3203Face does not directly lead the water of Beirui River into the underground, threateningmine safety.The research results laid a foundation for further study of overburden movement andfailure law of fully-mechanized top-coal caving mining in extremely thick coal seam, and it isalso of guiding significance for the safety production of coal mining under water body inHuating Mining Area.