Study On Support Technology Of Soft Rock Roadway In S2N8 Face Of Xiaokang Coal Mine

With the increasing complexity of mining conditions and the increasing depth of mining,the problem of instability of soft rock roadway in Xiaokang Mine is becoming more and more prominent.Based on the analysis of the measured data,the numerical simulation and the engineering practice,this paper analyzes the causes of the surrounding rock deformation under the original support scheme in the soft rock roadway of the traffic tunnel along the S2N8 working face in Xiaokang Coal Mine.A new support scheme of high strength anchor spray net with U-shaped steel retractable bracket and wall filling technology is designed.The numerical simulation model of S2N8 working face is established by FLAC3D numerical simulation software.The simulation results are compared with the measured data,and the accuracy of the numerical model is verified.After that,the original support and new support program were simulated and analyzed,the results show that the average convergence rate of the two roads is 11.28 mm/d under the condition of the original support scheme,and the average convergence rate of the roof and floor is 27.95 mm/d.The deformation and damage of the roadway are greatly affected by the mining,Which cannot achieve the effective control of the deformation and damage of the mining roadway.The new convergence scheme has an average convergence rate of the two roads is 3.42 mm/d and the average convergence rate of the roof and floor is 11.73 mm/d.By comparing the convergence rate of the two roads,the convergence rate of the roof and floor,the plastic circle of the surrounding rock under the two support schemes,and carried out on-site practical application,and the surface displacement of the roadway is monitored.Found that in the introduction of new support program,the roadway has been effectively controlled to meet the smooth mining of S2N8 working face,the new support to avoid a number of renovation.The economic analysis of the original support and the new support plan shows that under the same mining conditions,the new support scheme can save the cost of 32,283.05 yuan per meter roadway,not only to ensure the safe mining of the working face,but also reduce the mining cost,and improve the economic benefits of coal mines.