Research On Control Technology Of Coal Wall Spalling Of Large Mining Height Face In Xiaobaodang Coal Mine

Large mining height fully mechanized mining is the main mining method of thick coal seam,with the increase of mining height,the problem of coal wall spalling becomes more and more serious,which is one of the most difficult problems that restrict the safe and efficient exploitation of coal mine.Therefore,it is of great theoretical significance and practical value to study the coal wall spalling in fully mechanized mining face with large mining height.Based on Xiaobaodang coal mine fully mechanized face with large mining height as engineering background,by the methods of theoretical analysis,physical simulation and numerical simulation study on the coal wall spalling form and mechanics analysis,the coal wall spalling reason and put forward the large mining height fully mechanized working face coal wall spalling control technical measures.According to the Xiaobaodang coal mining conditions,the main reason of the coal wall spalling of 2-2 coal working face is that the coal body strength is small.Simulation experiment on 7.5m and 5m fully mechanized face with large mining height support working resistance and abutment pressure are analyzed by physical similarity results show that working face support setting load and working resistance can not meet the actual needs,resulting in coal wall under roof pressure,serious spalling;working face pressure when the support pressure peak the peak point of the coal wall,distance in front of the coal wall abutment pressure 70m,50m range increase sharply,soft coal body range,spalling tends to increase;the above two points are the main external local small coal mine working face coal wall spalling reason.In order to improve the coal wall stability,in 7.5m,5m production increased the support resistance to 13000kN and 9900kN in the actual production of high resistance to 20000kN and 13600kN,and ensure the advanced support the rock in front of the working face of roadway.Through the numerical simulation,the influence factors of three kinds of factors,such as the mining height,Bracket Support Strength and Help Support Strength plate,are simulated.The stope plastic zone graph has been in front of the coal wall coal coal wall damage area and the maximum horizontal displacement of the coal body size,the abutment pressure peak position from the coal wall horizontal distance,the results and the physical simulation experiment results.Based on the above results,the fully mechanized mining parameters of Xiaobaodang coal mine are optimized.According to the research,put forward the comprehensive measures for maintaining the control process of small coal mining:improving coal strength and support setting load and working resistance,and the timely forced caving support method,shallow depth of the coal cutting and strengthening production technology management.