Study On Instability Mechanism And Control Technology Of Main Roadway In Duanshi Coal Mine

The track roadway of Duanshi Coal Mine is affected by the mining of adjacent working faces,and the deformation and deformation of the roadway is more serious,which affects the normal production of coal mines.Based on the engineering background of Duanshi coal mine track and alleys,this paper analyzes the instability mechanism of the track and alleys by means of on-site measurement,numerical simulation and theoretical analysis.It also proposes reinforcement technology for the roadway affected by dynamic pressure,and targets the new roadway.The section proposes the corresponding surrounding rock control technology,and the main research results obtained are as follows:(1)Through the theoretical analysis of the elastoplastic zone of the surrounding rock of the roadway,it can be known that the original support strength is insufficient,resulting in serious deformation and deformation of the surrounding rock of the roadway.Through the numerical simulation to analyze the stress and deformation of the surrounding rock of the roadway,it is found that the leading support pressure generated at the end of the 3110 working face is the main cause of the instability of the roadway.(2)Aiming at the instability section of the track and alleys,starting from the improvement of the surrounding rock stress state of the roadway and the surrounding rock mechanical properties,a complete support scheme is proposed(removing the original support ? artificially expanding the section ? grouting ? Bolt support ? shotcrete).Through the numerical simulation to compare the support effect of different bolt support schemes,and considering the economic benefit factors,the scheme 2 is determined as the final support scheme.On-site observation and implementation of the support scheme,the deformation of the surrounding rock is as follows: the amount of roof subsidence is controlled within 65 mm,the bottom drum volume is controlled within 100 mm,and the distance between the two lanes of the roadway is controlled within 95 mm.The observations show that the support scheme can better strengthen the unstable track and alley.(3)For the new excavation section of the track and alley,the mining pressure technology at the end of the working face is proposed,and the influence of different propulsion speeds on the surrounding rock stress of the roadway and the surrounding rock deformation of the roadway is analyzed,and the advancing speed is finally determined to be 8m/d.By comparing and analyzing the surrounding rock stress environment and surrounding rock deformation of the roadway with 5m above the coal roof and 5m below the coal roof,it can be seen that the roadway is placed 5m below the roof to make the track and alleys better in the surrounding rock.The stress environment is more conducive to the surrounding rock control of the roadway.(4)According to the surrounding rock conditions of each section of the roadway and the deformation of the roadway,different targeted support schemes are selected.After the support parameters are changed,the support quality is improved and the support density is reduced.The number of anchors and the number of anchors are reduced by 4.2% and 50%,respectively,which reduces the drilling workload.