Study On Instability Caving Law And Coal Caving Of Coal And Strata In The End Zone Of Mechanized Caving Face In Yanzhou Coal Mine

The majority of the two ends of the full mechanized working face in our country don’t release top coal or just put a small amount of top coal.Study the fundamental reason is that the armored flexible chain conveyor uses rear ends unloading method leaving head,tail parts of the driver,leading to a narrow caving space and causing end zone coal difficult to recover.Therefore,this paper used on-site investigation,theoretical analysis,numerical calculation,an integrated research methods and measurement engineering practice combined analysis method and carried out caving face end zone and caving equipment arrangement space to determine,instability tip area of coal and rock collapse law,transport of coal and rock,caving of coal industrial test and other aspects of the law.In this paper,Yanzhou typical mechanized caving mine status quo,based on analysis of top coal losses end zone face top coal loss rate,study end zone to put the main technical problem of coal exist,to provide the appropriate technical countermeasures proposed in accordance with.Study end zone by the end of the discharge device arrangement side dump space to cross characteristics and caving to end the benefits,and to determine the end of the spatial extent of caving.By theoretical analysis,the size of the block model Face end hinged rear head plate broken,revealing the similarity ends with the overall migration law Comprehensive Face head after breaking caving roof structure;numerical simulation by 3DEC the establishment of fully mechanized coal caving face end zone rock computational model to study the distribution of stress field of surrounding rock displacement field end zone,and the roof with top coal caving mining face instability characteristics of surrounding rock stability of roadway and mining,etc.,top end zone for on-site coal release provided.By PFC3 D top coal of different hardness,caving region and process parameters on the end zone put off the flow of coal and rock as well as the influence of top coal recovery area on the tip of easy top coal caving Division presented a tip caving In principle,determine the tip caving reasonable coal region and process parameters.Combined with the actual conditions of Yanzhou Coal Mining 1306 Working Face in Dongtan,conducted a tip zone caving of field application,and measurement analysis face end top coal movement law area,roof movement law,the law of the bracket carries,roadway around rock deformation law,abutment pressure distribution etc.,proposed and implemented to improve the end zone of the top coal caving technology and recovery measures.Field application made good technical and economic results.