Research On Supporting Technology Of Auxiliary Transportation Roadway In 2-2 Mining Area Of Xiayukou Mine

The production of underground coal mine is inseparable from underground roadway.In this paper,a detailed field investigation is carried out in the auxiliary transportation roadway of 2-2 mining area of Xiayukou Coal Mine.Combined with the engineering geological data of Xiayukou Coal Mine,the instability characteristics of the roadway support structure and the causes of surrounding rock deformation and failure under the original support conditions are preliminarily analyzed.Focusing on the influence factors of roadway surrounding rock stability,the numerical simulation work was carried out,and the influence law of the influence factors on the stability of roadway surrounding rock was systematically analyzed.According to the analysis of the supporting effect of anchor mesh cable,two kinds of supporting schemes are designed and compared by numerical simulation,and the optimal scheme is selected.The rationality of the scheme was verified by field industrial test.The main research contents and achievements are as follows:(1)The field data of surrounding rock fissure development and in-situ stress in the auxiliary transport roadway of Xiayukou mining area 2-2 were measured and analyzed,the results show that: The surrounding rock elastic deformation and plastic deformation in a row,the early days of the late for crack extending discontinuous large deformation,such as malignant supporting structure appears outside anchor cable tray reverse distortion,anchor end bending,to protect the table cold wire drawing net tensile splitting strength failure phenomenon.In the shallow part,the fracture degree is large and the cracks develop to the range of anchor bolt,which is not conducive to the support of anchor bolt.In the deep part,the integrity of surrounding rock is better,which can give full play to the supporting function of anchor cable.The in-situ stress test shows that the maximum principal stress is horizontal stress,and the ratio of maximum principal stress to vertical stress is close to 1.8.It is concluded that the deformation and failure of surrounding rock are caused by the influence of fold structure,low strength of surrounding rock and unreasonable support parameters.(2)Numerical simulation analysis of the surrounding rock activities under different angles of maximum horizontal stress and roadway,it is concluded that with the increase of the Angle,the displacement and stress values of the two sides,roof and floor generally increase,but the displacement and stress changes of surrounding rock at different depths show regular changes at different angles.Through numerical simulation analysis and comparison of mudstone and sandstone surrounding rock,it can be seen that the harder the rock is,the higher the strength of surrounding rock is.Under the same stress condition,the deformation of soft rock is large and the plastic zone develops.(3)Based on the detailed analysis of the role of anchor mesh cable and other supporting structures in surrounding rock support and the synergistic action principle of anchor and cable,it is obtained that the original supporting side has low anchor diameter and strength,the pre-tightening force of anchor cable and bolt does not match,the stiffness of metal mesh does not match and the thickness of shotcrete is unreasonable.According to the above conclusions,two kinds of support schemes are designed and proposed to improve the supporting components.Through numerical simulation analysis and comparison,the optimal scheme is selected as the support scheme of the auxiliary transport roadway in 2-2 mining area.(4)Conduct on-site industrial experiments and engineering monitoring on the research results to ensure the construction quality of the support scheme and record the data on the support effect.Based on the analysis of the existing problems in the construction process,it is proposed to use the construction platform to ensure the Angle of the anchor cable construction and to use the exposed long anchor rod to solve the problem that the anchor rod can not be arranged close to the rock surface.The field test data show that the maximum displacement of surrounding rock is less than the allowable maximum displacement after adopting the high-strength stable anchor net support scheme,which maintains the stability of the roadway and achieves the engineering goal.The thesis has 42 figures,3 tables and 83 references.