Deformation Mechanism And Control Technology Of Surrounding Rock In Mining Roadway Of Soft Coal Seam In Fuyan Coal Mine

Aiming at the difficult problem of severe damage in roadway support of soft coal seam,this thesis takes 3109 transportation roadway of Fuyan Coal mine in Shanxi as the research background,based on field investigation,laboratory test,theoretical analysis,numerical simulation and field industrial test,studies the deformation mechanism and control technology of surrounding rock of mining roadway of soft coal seam.The main achievements are as follows:（1）Based on the deformation and failure mechanism of roadway surrounding rock in soft coal seam,a mechanical structure model of surrounding rock of rectangular stope roadway is established.The radius of plastic zone of surrounding rock is calculated as 5.23m by the formula of plastic zone radius of surrounding rock.Moreover,the research shows that the radius of plastic zone of roadway is mainly affected by the strength and support resistance of surrounding rock under the condition of a certain surrounding rock stress and roadway size.However,relatively speaking,it is more influenced by the strength of rock mass itself.For soft coal seam,improving the cohesion and internal friction Angle of coal mass of two sides,namely improving the strength of rock mass itself,can more effectively control the stability of surrounding rock of roadway.（2）Based on the deformation and failure mechanism of roadway surrounding rock in soft coal seam,a mechanical structure model of surrounding rock in rectangular stoping roadway was established.The radius of plastic zone of surrounding rock was calculated as 5.23m by the formula of plastic zone radius of surrounding rock.The study of plastic zone shows that the radius of plastic zone is mainly affected by the strength and support resistance of surrounding rock,but is more affected by the strength of rock mass.For soft coal seam,the stability of surrounding rock can be effectively controlled by improving the cohesion and internal friction Angle of two sides coal,namely improving the strength of rock mass itself.（3）Based on the deformation and failure mechanism and characteristics of mining roadway in soft coal seam,grouting reinforcement technology is proposed to control the deformation of roadway surrounding rock in soft coal seam.Combined with the loading mechanism of grouting reinforcement in soft coal seam and the mechanical analysis of roadway in soft coal seam,it is concluded that when the depth of plastic zone on two sides of roadway decreases after grouting,the equivalent width of roadway will also decrease accordingly,and the deformation and floor heave of two sides of roadway will also decrease.（4）Based on the actual situation of the field,the grouting parameters are determined by theoretical calculation,and the grouting reinforcement scheme is proposed in the side part of coal pillar.FLAC^3D simulation software is used to conduct simulation research on the grouting reinforcement model.The results show that the tunnel deformation is greatly reduced after grouting reinforcement technology is adopted,the displacement of two sides is reduced to 290.71mm,which is reduced by 79.6%,and the displacement of roof and floor is reduced to 299.04mm,which is reduced by 79.1%.（5）Rock pressure monitoring,drilling and mechanical testing are used to monitor the state of surrounding rock in the industrial test section.The results show that the integrity of the surrounding rock in the test section is good,the bond degree between the grout and the crack of the surrounding rock is good,and the strength is increased by more than 40%.Compared with the original support condition,the deformation of the roadway surrounding rock is greatly reduced,the displacement of the roof and floor of the roadway is reduced by 647mm,and the displacement of the two sides is reduced by 757mm.The deformation degree of the surrounding rock is low,and the roadway can meet the mining demand of 3109 fully mechanized mining face.