Failure Mechanism And Surrounding Rock Stability Control Of Large Section Roadway In Thick Seam Of Sihe Mine

The stability of the surrounding rock of the roadway is an important factor in coal mining.Therefore,the stability control of the surrounding rock of the roadway is a decisive factor for effectively improving the stability of the roadway roof.The overall storage characteristics of the Sihe Coal Mine are thick coal seams,shallow burial,and large cross-sectional dimensions.It is easy to cause serious structural damage to the roadway coal bank when mining the roadway face,which becomes an important risk for mining production operations.Based on the characteristics of the 5-2 coal seam in Sihe Coal Mine,this study focused on the 15207 roadway excavation status,using theoretical analysis,numerical simulation,theoretical simulation experiment and field observation data analysis and other research methods to comprehensively measure and determine the structure and structure of the roadway coal bank.Mechanics data,analysis of the causes and various influencing factors of the roadway coal side damage,analysis of the main manifestations of coal side damage,targeted analysis of the damage manifestations and study of the coal side support methods,and explanation of the roadway coal side support methods.The reasons and pros and cons of the coal mine,and finally came up with the overall protection and reinforcement plan for the coal seam.The main conclusions are as follows:(1)Through observation and analysis,it is concluded that Sihe Coal Mine 5-2 coal seam roadway has three main failure states,namely the destruction of the shoulder angle of the road side,the outward bulging of the middle part of the road side and the local surface of the road side.The sex falls off into pieces.(2)According to observation and analysis,the main reasons leading to these forms of damage are obtained.(a)Observe the excavation process of the roadway,record and derive realtime mechanical data in all directions of the roadway slab,and perform mechanical modeling of the internal horizontal displacement,internal vertical stress state and horizontal stress state of the surrounding rock of the roadway slab.Analyze and express,comprehensively consider the actual conditions of the plastic zone and the fracture zone,analyze the main factors that affect the state of the ledge during the excavation process of the roadway and the main reasons that are likely to cause the road ledge to break during the mining process,and finally weigh the mechanical indicators of each direction,the coal bed rock The degree of influence of main influencing variables such as state,burial depth,and coal body elasticity on the rupture of road ledge.Substitute the data of the length,width and height of the roadway and the compression index of the roadway into the Design-Express software.Through simulation experiments,the actual influence of the changes of various indexes on the displacement of the roadway coal side deformation is studied.(b)In the process of excavating the roadway,the internal stress state of the coal and rock at the roadway still has the following changes compared with the stress distribution state before mining: the horizontal stress is significantly reduced,the vertical stress is significantly increased,and both horizontal and vertical the before and after changes of the stress index are likely to cause structural damage to the rock formation of the roadway ledge.(3)After analyzing the stress and compression conditions of the target roadway in the target coal seam,the stabilization measures for the strong support of the roadway in the mining face are proposed.The numerical simulation model is used to carry out the theoretical analysis of 13 conditions.After comprehensive measurement and comparison,it is concluded that by protecting 4 ?18×3000mm rebar anchor rods and controlling the row spacing form of 1000×2000mm,the area that can be deformed can be plasticized.The range is controlled in a small range,which effectively improves the stability and reliability of the surrounding rock structure of the roadway ledge,and greatly reduces the deformation and displacement of the surrounding rock of the ledge.