Study On Surrounding Rock Deformation Mechanism And Roof Cutting Pressure Relief Control Of Thick Coal Seam Roadway Facing Mining In Xiegou Coal Mine

In the production process of tens of millions of tons of coal mines in China,in order to reduce the number of moving backwards,reduce the loss of coal resources,and ensure the normal replacement of coal mines,it is often encountered that the working face and drifting face meet each other,or the roadway is affected by the working face mining,which seriously affects the safe and efficient mining of coal resources.In this thesis,taking 18106 roadway in Xiegou Coal Mine as the background,the deformation mechanism of surrounding rock and hydraulic fracturing pressure relief control technology are studied by using theoretical analysis,laboratory experiments,numerical simulation and field practice.The main results are as follows.（1）The characteristics of mine pressure behavior and the influencing factors of mine pressure behavior in 18106 material roadway are systematically analyzed.The uniaxial compressive test and brazilian splitting test are carried out,and the fracturing ability of coal seam and roof in Xiegou Mine is analyzed.The uniaxial compressive strength of 8^#coal is 6.98 MPa,the tensile strength is 1.25 MPa,the compressive strength of sandstone roof is 33.71 MPa,and the tensile strength is 3.50 MPa.The fracturing ability of coal seam and roof is good,but the fracturing ability of medium-coarse sandstone is stronger than that of 8^#coal.（2）The numerical simulation method is used to analyze the surrounding rock deformation law of 18108 working face mining rock activity and 18106 roadway,and the deformation characteristics of adjacent working face in different influence stages are obtained.It is concluded that the advanced abutment pressure of adjacent working face and the roof activity after mining are the main influencing factors of the deformation of the roadway,but the influence of the roof activity after mining is more obvious.（3）Based on the deformation mechanism of mining roadway and the principle of stress transfer and pressure relief of hydraulic fracturing,the principle of determining the reasonable time of hydraulic fracturing is proposed.The influence of different fracturing heights on the deformation of surrounding rock of roadway under mining is analyzed,and the reasonable temporal and spatial relationship of hydraulic fracturing is obtained.It is concluded that the reasonable time of hydraulic fracturing construction is to start construction before 187 m between the working face and the roadway under mining.The distance between the starting point and the working face L₁ is greater than35 m,and the distance between the starting point and the roadway under mining L₂ is greater than 152 m,which satisfies L₂>96+1.6L₁.The fracturing thickness of medium-coarse sandstone roof should be greater than 10 m.（4）The hydraulic fracturing pressure relief scheme is formulated,and the field construction and effect observation are carried out.The observation results show that the hydraulic fracturing produces effective cracks in the roof,and the deformation of roadway surrounding rock in the fracturing section is significantly reduced compared with that in the non-fracturing section,which has achieved remarkable control effect.This paper has 64 pictures,14 tables,and 95 references.