Study On Coal Rock Migration Law And Drawing Technology Of Fully Mechanized Caving Face With Large Dip Angle And Thick Coal Seam

The status of coal resources as the primary energy source will not change for a long time in the future,and it will still have a dominant position in the development of economy and science and technology.However,due to long-term mining in my country,coal seams with better mining conditions have become less and less.Most mining areas are shallow and easy to mine coal resources in a short period of service.The coal seam with high dip angle is one of the difficult coal seams.As a large country with abundant coal reserves,China’s large-dip coal seam reserves account for about one-fifth of the country’s coal reserves,and its annual output accounts for about one-tenth of the country’s annual coal output.This topic with large dip Angle for actual engineering conditions,specially thick coal seam fully-mechanized sublevel caving mining working face in meng kiln coal mine 11505 working face,on the basis of field investigation and measured,using the data collected,physical experiment,theoretical analysis and numerical simulation methods,with large dip Angle under different mining thick coal seam fully-mechanized sublevel caving mining working face coal rock and coal process were studied.The main research contents and results are as follows:(1)Investigate the actual situation of the 11505 fully mechanized caving working face in Mengjiayao Coal Mine,analyze the geological conditions and geological structure of the working face,conduct in-situ stress tests and conduct on-site sampling for basic mechanical property experiments,and obtain the basic mechanical parameters of coal and rock at the working face.(2)Theoretical analysis of the factors affecting the caving of the overlying coal and rock during the mining of the fully-mechanized caving face of the large-dip angle and extra-thick coal seam,combined with the obtained basic mechanical parameters of the coal and rock,the FLAC3D numerical simulation software was used to simulate the stress of the working face under different mining heights According to the change law of the field and displacement field,it can be concluded that the appropriate increase of the mining height can play a certain role in the crushing of the overlying coal and rock,and the cavitation of the overlying coal and rock with different mining heights can be sorted.(3)Through the combination of theoretical analysis and discrete element numerical simulation,the machine mining height,coal caving step distance,coal caving principle and coal caving method of 11505 working face were studied.The coal step distance is 1.6m,and the single-round sequential upward coal discharge is the construction method of the research object on the site.(4)According to the actual conditions of Mengjiayao Coal Mine and the selected reasonable coal drawing process parameters,the main equipment of the 11505 working face is selected,and the reasonable process coordination is studied to verify the rationality of the coal drawing process parameters and the selected equipment.The reliability of the working face was obtained by statistics,and the main technical and economic indicators of the working face were obtained,and the migration of the overlying coal and rock on the working face was measured.There are 46 pictures,32 tables and 90 references in this article.