Study On Caving Characteristics And Caving Leakage Risk Mechanism In Thick Coal Seam With A Stratum Of Gangue In Fully-mechanized Mining With Top Coal Caving

Based on the geological and mining technical conditions of No. 8102 face in the Guobei Coal Mine, wall- rock migration regularity,a stratum of gangue of caving and put influence at surface layer caving a stratum of gangue leakage risk mechanism under the condition of soft coal, thick-hard roof and thick coal seam with a stratum of gangue have been studied by the integrated means of theory analysis,numerical simulation and field measurement.Firstly,the paper analyzes broken feature over top coal with thick coal seam with a stratum of gangue,it is to say, which analyzes strength feature and deformed feature of top coal.Secondly, a stratum of gangue of top coal stability has been studied and mechanical model of a stratum of gangue through the analysis of actual force state. Based on the study,broken effect of a stratum of gangue ,top-coal drawing feature and Leakage risk characteristics are analyzed. By the way of distinct element numerical simulation, according as the distribution features of stress, displacement and failure field in top coal, broken effect of a stratum of gangue and top-coal drawing feature are analyzed through altering influencing factors of a stratum of gangue such as different thickness,different depth,different strength and characristics of coal mining face leakage risk etc. The law of fracture and instability and leakage risk of top coal in thick coal seam with a stratum of gangue in fully-mechanized mining with top coal caving is obtained after analysis being done. Finally, combining research conclusions with geological conditions of fully mechanized top coal caving face No.8102 in Guobei coal mine, the results are correct by site measurement, and good technique and economical effects are obtained.