Research On Support Technology Of Mining Roadway Under Complex Mining Stress

Aiming at the problems of complex dynamic pressure,asymmetric stress distribution and other problems faced by the return roadway excavation of 4102 working face of Si Tong Coal Industry Co.,Ltd.,combined with the actual needs of specific projects,comprehensive analysis of theoretical analysis,laboratory similar material simulation experiments,FLAC3 D numerical simulation experiments On-site monitoring and other methods were used to study the evolution and deformation law of the surrounding rock stress field of the 4102 face of Si Tong Coal Industry under different roadway coal pillar widths.The deformation law of surrounding rock under the influence of double mining stresses in residual bearing pressure and advance bearing pressure of working face has determined a reasonable roadway pillar width and safe and economic roadway support scheme.(1)Through field sampling,study the rock types and mechanical parameters of the surrounding rock of the mining roadway,and provide basic data for similar simulation experiments,numerical simulation experiments and roadway support design;according to the specific conditions of the mining area,detect the looseness of the existing roadway the depth of the ring can be obtained through analysis.The existing surrounding rock loosening range of the roadway is between 2.5m-4m,which belongs to the big loosening ring roadway.(2)A DGS-4 channel microcomputer controlled electro-hydraulic servo similar material test bench was used to conduct a similar simulation experiment,respectively simulating the deformation of the surrounding rock of the return air lane when the coal pillar width of the roadway is 5m,10 m,15m,20 m,25m and 30 m It is concluded that with the increase of the width of the coal pillars in the roadway,the basic law of the deformation of the surrounding rock of the roadway is obtained.The XTDP three-dimensional photogrammetric measurement system is used to collect data from the observation points.Vector illustration of surrounding rock deformation under column size.The results of the vector analysis indicate that when the width of the coal pillars in the roadway is 25 m and 30 m,the deformation of the surrounding rock of the roadway is 203 mm and 189 mm,which is in line with the actual requirements of the project.(3)The FLAC3 D numerical simulation software was used for numerical simulation to simulate the return air lane of 4102 working face of Sitong Coal Industry,and the surrounding rock stress of the roadway pillar width of 5m,10 m,15m,20 m,25m and 30 m was simulated.Based on the evolution and deformation laws of the field,the displacement cloud map and stress cloud map of the surrounding rock of the roadway under the coal pillars with different widths are obtained,as well as the displacement of each monitoring point.According to the data,with the increase of the width of the coal pillars of the roadway,the roadway is gradually away from the high stress field.When the width of the coal pillars of the roadway is 25 m,the displacement of the monitoring point is below 200 mm,and the simulation of the width of the coal pillar is 25 m The influence of the working face advancement on the displacement of the surrounding rock of the roadway.Under the influence of the leading bearing pressure of the working face,the surrounding rock stress is redistributed,but the overall displacement is still within the safe range.(4)Combining similar material simulation experiments and numerical simulation experiments,the width of the coal pillars of the return roadway protection in the 4102 working face was initially determined to be 25 m,and a full anchor cable support scheme was formulated to effectively reduce the rea close to the goaf The surrounding rock of the tunnel is deformed,and the displacement of the observation point on the left side of the roof is reduced by 37mm(17%).A test section of 100 m was selected on site for on-site monitoring.By formulating a monitoring plan and analyzing the monitoring data,it was preliminarily determined that the width of the coal pillar and the supporting plan met the actual requirements of the project.