Research On Disaster Causing Mechanism And Control Of Overlying Stratum Structure Of 7132 Panel Of The Lower #3 Coal Seam In Tianchen Coal Mine

In recent years,China's shallow coal resources have been increasingly depleted,and most of the main coal production mining areas have gradually entered the state of deep mining.With the obvious improvement of China's coal mining technology level and coal machinery equipment manufacturing level,China's well engineering coal mine longwall work The width of the face is getting larger and larger,and more and more long working faces have appeared.Super-long working face has intense pressure during the mining process,which is mainly manifested in that the ultra-long working face is more prone to coal wall flank,excessive support resistance,and even coal and gas dynamic disasters such as coal and gas outburst and rock burst.In this paper,the 7123 panel of the lower #3 coal seam of Tianchen Coal Mine was selected as the research object,and the movement law of the overlying rock structure and the disaster-causing mechanism and the method of preventing rockburst in the deep long ultra-long working face were studied.Through numerical calculations,physical similarity simulation experiments,on-site monitoring and industrial tests and other research methods and technical methods,the law of overburden rock movement and the distribution of supporting pressure on the working face of the deep well were studied,and the mining of the ultra long working face was explored.During the process of rockburst suppression,the prevention and control measures of rockburst were implemented according to the actual engineering conditions of the working face,which ensured the safe mining of the coalface and achieved good application results.The thesis mainly achieved the following research results:(1)By using the method of numerical simulation to study the slant length of the working face at 200 m and 360 m,the characteristics of the advance bearing pressure evolution of the working face are obtained.When the oblique length of the working face increases from 200 m to 360 m,the maximum leading bearing pressure of the working face increases from 42.24 to 58.17,the stress concentration factor increases from 2.82 to 3.88,and the position of the maximum leading bearing pressure of the working face increases from 4.5m to 5.5m,increasing the influence range.(2)Through the analysis of stress monitoring data,the influence distance of the leading bearing pressure of the working face is 70.3-85.1m,and the position of the bearing pressure increases sharply 30 m from the coal wall;through theoretical calculation and numerical simulation,the working face is promoted when the working face is 360 m long At 50 m,100 m,150 m,200m,300 m,and 360 m,the stress concentration factors are 2.24,2.74,2.91,2.96,2.99,and 3.88,respectively.(3)Through the simulation of similar materials,it reveals the development characteristics of roof separation and movement characteristics of overburden structure in the mining of ultra-long working face in deep wells.When the key layer breaks for the first time,vibration occurs and the vibration is transmitted to the coal body,and additional stress is generated in the coal body,Thereby triggering rockburst;thereafter,with the periodic breakage of the key layer,periodic vibrations and periodic impacts occur.(4)The shorter the working face,the greater the impact of the periodic pressure step on the working face pushing progress,and the unevenness of the periodic pressing step is more prominent.The longer the working face,the longer the working pressure on the working face is.The smaller the impact of the progress,the more stable the step of the pressure is.At the same time,as the length of the working face increases,the parallelism of the broken line of the pressure to the roof and the working face is higher.The breakage of the key layer of the overburden stope in the ultra-long face is smaller than that of the ordinary face.Therefore,the ultra-long fully mechanized top-coal caving face has low intrusive strength and uniform pressure distribution,and the inrush of the main key stratum of overburden rock will occur,so it is necessary to strengthen prediction and effective control.The paper contains 38 Figures,9 Tables,and 122 References.