Flexible Anchorage Of Road Driving Along Goaf With Large Dip Angle Under Goaf Research And Application Of Supporting Technology

With the reduction of coal resources,some mining areas have begun to turn to coal seams with complex geological conditions for mining.However,short-distance coal seam mining faces a series of problems,such as coal seam inclination,thickness,and seam spacing.Make the same roadway support multiple ways.When driving along the gob under the short-distance mined-out area,the roof of the coal seam is damaged to different degrees and the inclination angle changes,which brings support difficulties to the driving.These issues need to be resolved.This paper takes the roadway excavation in the 2nd lower 06 coal seam of Yufeng Mine as the research object,and studies the stability of the roadway along the goaf from the aspects of coal seam spacing,coal seam inclination,roadway layout,coal pillar width,etc.,to provide a basis for roadway support.The main difficulty of the roadway support is the driving along the gob below the goaf,which is affected by the goaf of the upper coal seam,the roadway inclination changes greatly,the local structure is many,the roof is broken,the roadway deformation is large,and the anchor net is broken.(1)Theoretical analysis of the stress distribution laws of the stope and coal pillars in the upper coal seam mining area,the results show that the lateral supporting pressure is formed around the upper coal seam mining,and the edge load in the goaf area is low,the central load is high,and the stress is large.The coal pillar is subject to greater stress,and the formula for the stress distribution law of the upper coal pillar roof is deduced.(2)Calculate the damage range of the upper coal seam floor based on the slip line theory.The results show that: the floor damage range of upper coal seam mining is 5-10 meters,which affects the roof support of the roadway.(3)Taking the change of rock thickness between coal seams as the research object,analyze the stress distribution law of roadway with different coal seam spacing.With the increase of the layer spacing,the horizontal stress on the coal pillars of the roadway decreases with the increase of the layer spacing.The horizontal stress on the coal pillars is the highest at 4m from the surface of the roadway,which decreases to both sides,and the distance between the coal seams increases.Greatly conducive to the stability of the coal pillars,short-distance coal seam mining is not conducive to the stability of the coal pillars along the goaf roadway.(4)Stress analysis of roadway with different coal seam dip angles: the stress concentration range of the surrounding rock of the roadway increases with the increase of the coal seam dip angle,and the stress concentration on the side of the coal pillar is much greater than that on the solid coal side.The continuous increase of the dip angle of the coal seam increases the partial load the trend of.As the inclination angle of the coal seam increases,the shear stress shows a trend of “increasing first and then decreasing”;when the inclination angle of the coal seam is 30° to 35°,the peak shear stress of the floor reaches its maximum and the plastic zone gradually decreases.(5)Stress analysis of different coal pillar widths: Considering the coal pillar's own bearing capacity and stress environment,the reasonable width of the coal pillar is 6meters through numerical simulation analysis and theoretical calculation.(6)Industrial test: Combining the research of different chapters,put forward the support technology and plan of roadway driving along the gob under different coal seam inclination angles.Through the on-site industrial test,the monitoring results of mine pressure and roof separation show that the new support plan makes The amount of roadway deformation is effectively controlled.This paper has 53 pictures,10 tables,and 59 references...