Study On The Repairing And Reinforcing Technology Of Repetitive Mining Roadway Near Coal Seam Group In Faer Coal Mine

In the process of repeated mining of close-distance coal seams,the coal pillars of the retaining lanes left by the upper coal mining will generate stress concentration zones and be transmitted in the floor rock strata.The coal seam group floor roadway is greatly affected by multiple mining,and the surrounding rock of the roadway The deformation is more obvious.Therefore,it is of theoretical significance to systematically study the surrounding rock control technology of the roadway under repeated mining.Based on the actual background mining and roadway support,the deformation characteristics of the surrounding rock and the surrounding rock lithology are determined according to the actual mining and roadway support in Guizhou,and the cause of deformation of the roadway is analyzed.Supporting theory,proposed the repair and reinforcement technology of repeated mining roadway in close-distance coal seam group,and adopted the methods of theoretical analysis,numerical simulation and on-site industrial test to systematically solve the problems of roadway repair and reinforcement and reasonable retention of coal pillar protection.The main research results are as follows:（1）According to the deformation characteristics and failure reasons of the roadway,based on the principle of strengthening the support of weak structural parts,a roadway repair and reinforcement scheme with high-performance anchors,small-aperture prestressed anchor cables and grouting reinforcement is proposed.Aiming at the repeated mining effects of multi-coal mining on the floor roadway,the stress transfer mechanical model of the bottom coal seam mining floor was established,which provided a theoretical basis for the problem of retaining coal pillars in the roadway.（2）The on-site investigation and theoretical calculation are used to determine the parameters of roadway repair and reinforcement.The numerical simulation software Phase is used to compare and analyze the support effect of roadway under different support schemes,and finally propose a reasonable repair and reinforcement scheme.（3）According to the actual situation of the site and the conditions of coal seam occurrence,the numerical simulation software FLAC^3D was used to simulate the arrangement of the same width coal pillars,the spacing and the pressure relief of different width coal pillars,and the simulation results were obtained.The mining of close-distance coal seams has the least impact on the roadway.Comparing the effects of 1 coal pressure relief and 3 coal pressure relief,it can be seen that under the condition of 1 coal pressure relief,the rail roadway is less affected by the stress caused by the mining of multiple coal seams.（4）Through the industrial test,the determined repair and reinforcement scheme was tested and a successful application was achieved.The surrounding rock of the roadway is well controlled,and the deep displacement and surface displacement increment of the roadway are gradually decreasing in the overall monitoring data until it is basically stable.The repair and reinforcement scheme has been successfully applied and the service life of the roadway has been improved.