Study On Mine Pressure Behavior And Surrounding Rock Control Of Bottom Extraction Roadway In Licun Coal Mine

As a connecting channel between the surface and underground ore bodies,the roadway plays an important role in transportation,ventilation,drainage and pedestrians during the mining process.Before the excavation of the 3301 return air roadway in the third mining area of Licun Coal Mine,the 3301 return air bottom suction roadway has been supported and the surrounding rock is in a stable state.With the excavation operation of the 3301 return air roadway,the roof strata of the 3301 return air bottom suction roadway in the structural area are developed,and the surrounding rock of the side is broken.Therefore,it is of great significance for coal mine safety production to study the surrounding rock control technology in the case of roadway deformation and failure caused by excavation disturbance in the area affected by geological structure.Based on the engineering background of surrounding rock deformation of 3301 return air bottom pumping roadway in Licun Coal Mine,this paper adopts the methods of field investigation,theoretical analysis,numerical simulation and field industrial experiment,The main conclusions of the research on surrounding rock control technology are as follows :(1)Based on the surrounding rock loose circle of underground roadway in mining area,regional ground stress test and physical and mechanical experiments of coal and rock samples,the deformation and failure characteristics of surrounding rock disturbed by adjacent roadway excavation are analyzed,and the influencing factors of surrounding rock stability of 3301 return airway are summarized :high ground stress,low surrounding rock strength,excavation disturbance and regional structure;(2)According to the numerical simulation results,based on the stress evolution law of the floor of 3301 return air roadway,the displacement evolution law of 3301 return air bottom pumping roadway,and the advance abutment pressure evolution law of 3301 return air roadway excavation,the failure law of surrounding rock of 3301 return air bottom pumping roadway is analyzed;(3)Based on the failure mechanism and stability control technology of roadway surrounding rock,according to the failure characteristics of different surrounding rock sections,combined with theoretical calculation,the optimization scheme of roadway with different applicable conditions is put forward.In the serious broken section of the roadway,the second optimization scheme is adopted,that is,the roof is supplemented with anchor cable and the shed is erected,or the third optimization scheme is adopted,that is,the roof is supplemented with anchor cable and the shed is erected.At the same time,FLAC3 D numerical simulation is used to compare and analyze the surrounding rock control effect of the optimization scheme.It can be seen that the support effect is sorted from weak to strong as optimization scheme one,optimization scheme two and optimization scheme three,which are better than the original scheme.(4)The field industrial experiment is carried out on the first optimization scheme.According to the monitoring of the anchor cable force meter and the roof separation instrument,the data show that the roof of the 3301 return air bottom pumping roadway does not produce obvious displacement after optimization,and the control effect is good.Through the research of this paper,it not only optimizes the support scheme of the broken area of the surrounding rock of the 3301 return air bottom pumping roadway,improves the stability of the surrounding rock of the roadway,and provides experience for the control of the surrounding rock of the roadway under the influence of adjacent mining,which can provide reference for similar projects.