Surrounding Rock Under The Influence Of Mining In 3104 Return Airway Of Zhaozhuang Mine Research On Control Technology

Based on the engineering research background of 3104 return air roadway in Zhaozhuang Mine,on the basis of field investigation and analysis,this thesis carries out the physical and mechanical properties test of coal and rock mass,on-site peeping of surrounding rock fissures and on-site monitoring,and analyzes the influencing factors of surrounding rock stability and the causes of instability and failure.The variation law of surrounding rock deformation and support bearing capacity under the influence of dynamic pressure is analyzed by theoretical analysis and numerical simulation.On this basis,a reasonable reinforcement scheme of roadway surrounding rock support is proposed,and the influence law of coal pillar size on the stability of roadway surrounding rock is analyzed,which provides reference for similar roadway support and working face design in Zhaozhuang Mine.The feasibility of the reinforcement support scheme is verified by the field industrial test.The main results are as follows :(1)The 3104 return air roadway is a development roadway on the side of the stop coal pillar in the large mining height working face.Through the field investigation of the surrounding rock deformation of similar roadways,it can be seen that after the strong mining influence of the adjacent working face,the deformation of the surrounding rock of the roadway is mainly roof subsidence and two-side internal displacement.In some areas,there are also phenomena such as broken anchor cables and serious damage to supporting structures.It is concluded that the mining influence of large mining height working face,weak and broken roadway surrounding rock and low support strength are the main factors leading to roadway deformation and instability.(2)The variation law of surrounding rock stability during roadway excavation and working face mining under the original support conditions was compared and analyzed.During the roadway excavation,the overall stability of the surrounding rock of the roadway remained good.After the influence of dynamic pressure,the deformation and failure degree of the surrounding rock increased significantly,and the development range of the plastic zone expanded and showed asymmetry.(3)The control principle of surrounding rock stability of dynamic pressure roadway is analyzed.According to the synergistic mechanism of bolt-anchor cable,the strengthening technology of roadway support is put forward from three aspects :strengthening roadway support strength,optimizing support design and scientific pressure relief.The most reasonable pre-tightening force matching value is calculated by the bolt-cable pre-tightening force matching formula,and the reinforcement support scheme of 3104 return air roadway is put forward according to the phenomenon and cause of roadway instability and failure.(4)The numerical simulation method is used to analyze the deformation and failure law of surrounding rock of roadway after reinforcement support.The simulation results show that the superposition effect of stress concentration zone of surrounding rock of roadway after reinforcement support is weakened,the development range of plastic zone is obviously reduced,and the deformation and failure degree of surrounding rock is greatly improved,which verifies the feasibility and rationality of the support reinforcement scheme.The influence of coal pillar size on the deformation of roadway surrounding rock and the change law of supporting bearing capacity is analyzed.The simulation results show that the stability of roadway can be maintained by appropriately reducing the size of coal pillar within a reasonable range,which not only ensures the safety of mine production work but also improves the recovery rate of coal resources.(5)The field test results show that after the roadway support is strengthened,the deep separation amount of the surrounding rock and the surface displacement of the surrounding rock during the mining period of the working face are reduced,the active support effect of the anchor cable is fully utilized,and the overall damage degree of the surrounding rock is small,which meets the safe and efficient production needs of the mine.There are 50 figures,9 tables and 90 references in this thesis.