| The mining depth of 23160 working face in Pingmei No.4 Coal Mine has exceeded 800m,which belongs to typical deep mining.The damage of mining roadway in mining face is difficult to repair,which seriously affects the safety and normal production of the mine.Therefore,it is of great research significance and application value to study the support scheme along the trough in 23160 coal seam mining face for improving the economic benefit and safety production of the mine.Aiming at the failure and deformation of 23160 conveyance chute in Pingmei No.4 Coal Mine,based on the analysis of mine geological mining conditions and roadway surrounding rock conditions,through field and laboratory tests,theoretical calculation and analysis,combined with numerical simulation calculation and analysis,the support scheme design of 23160 conveyance chute in Pingmei No.4 Coal Mine was completed.Based on the laboratory test and analysis of surrounding rock lithology in 23160 working face of Pingmei No.4 Coal Mine,the hardness coefficient of surrounding rock mainly composed of silty mudstone is between 3 and 6,which belongs to medium-hard rock strata,and the mine hydrogeological conditions belong to a simple type.Based on the analysis of the degree,characteristics and types of roadway failure,the roadway section form is analyzed by field test method combined with numerical simulation calculation method.It is shown that under the geological conditions of the mine,the circular rectangular roadway with 800 mm cross-section shape reduces the stress concentration factor and is beneficial to the control of surrounding rock deformation in deep mining.Based on theoretical analysis and numerical simulation method,the supporting scheme of 23160 transport channel is determined:bolt mesh support is adopted in normal section,the shape of section is circular rectangular roadway,the row spacing between bolts is 800*1000mm,the specifications of bolts are MSGLW-400/M24-22*2500mm high-strength bolts,four bolts are arranged in the roof,four in the high side,three in the low side and three in the middle of the middle of the roof and two sides.A 6500 mm anchor cable is arranged at the part and arc corner,and the support of straight wall and semi-circular arch section and roof is adopted in the fractured section of surrounding rock.The field application and observation of the scheme show that the supporting effect has been obviously improved.The roadway deformation is controlled within a reasonable range,the monthly driving speed has been increased by 25%,and the final construction period has been shortened by 36 days;the amount of bolt used has been reduced by 22.3%in the 1200m transport channel,and the amount of anchor cable has increased by 8.1%,which saves the labor cost and reduces the comprehensive cost by 8.9%.The research results have application and popularization value for the safe mining of 16.17 coal seam in Pingmei No.4 Coal Mine. |
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