Failure Analysis And Repair Technology Of Bearing Structure Of Soft Rock Roadway With Coal Seam In Deep Roof

At present,coal is still the main resource used in China,and coal mining is also developing in depth.The deep environment is different from the shallow environment.Both the stress of surrounding rock and the joint structure of rock stratum are very complex,which also poses a challenge to coal mining and roadway support.The three-level Wuer belt uphill roadway of the sixth mining company of Pingmei Group is a deep buried roadway.The roof rock structure of the roadway is complex,which is not only inclined and staggered,but also close to the upper coal seam and mixed with coal lines in the middle.The roof and floor of the roadway are seriously deformed,and the anchor support structure is deformed and damaged in many places.The roof and floor of the roadway are seriously deformed,and the anchor support structure has produced many deformations.The belt transportation system is laid in the roadway,which also restricts the repair of roadway support.Therefore,based on the surrounding rock environment and engineering field data of the belt uphill roadway in Pingmei No.6 mine,using the theoretical analysis and FLAC3 D numerical simulation analysis method,this paper analyzes the failure evolution of the anchorage bearing structure of the soft rock roadway with coal seam in the deep roof,optimizes the repair scheme of the belt uphill roadway,and applies the repair scheme to the engineering field,the main conclusions are as follows:(1)Through the investigation of the belt uphill roadway and the electron microscope scanning experiment of the samples,the characteristics of the in-situ stress,the composition of the surrounding rock and the development of joints of the belt uphill roadway are obtained.The cantilever beam theory is applied to the mechanical analysis of the shoulder of the arch roadway,the stress transfer of the roof of the rectangular roadway is theoretically analyzed by using the composite beam theory,and the deformation and failure mechanism of the arch roadway and the rectangular roadway is obtained.The influencing factors of anchor bearing structure failure and roof deformation of different roadway sections are analyzed.It is concluded that the intercalated coal seam in roadway roof and roadway section size are the main factors affecting roadway deformation.(2)Using FLAC3 D numerical simulation analysis method,combined with the surrounding rock environment of the roadway up the mountain with belt,the influence law of the vertical stress distribution of the roadway surrounding rock and the variation law of the roof displacement are numerically simulated under the conditions of different roadway sections,the thickness of the seam sandwiched in the roadway roof and the roadway section size.It is concluded that: 1)Under the condition that there are intercalated coal seams in the deep roof,the rectangular roadway is easier to support the roof than the arch roadway;2)The greater the thickness of the roadway roof with coal seam,the more serious the deformation of the roadway roof;3)Combined with the analysis results of roadway section size,it can be concluded that placing the intercalated coal seam in the roof on the two sides of the roadway after roadway expansion is more conducive to the stability of the roadway.(3)According to the analysis results,the expansion design scheme for the belt uphill roadway is put forward,and the anchor support parameters are optimized.According to the field monitoring results,the optimized repair scheme has achieved good roadway deformation control effect and effectively maintained the safe operation of the belt uphill roadway.