Research on surrounding rock control and support technology of mining face crossing oblique empty roadway
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Abstract
In order to solve the problem of stability control and support technology of roadway driving in the old mining area, based on the analysis of the stability of roadway surrounding rock in the old mining area, the numerical simulation of the movement law of mining face crossing oblique empty roadway in the old mining area is carried out. The stress distribution of the surrounding rock of oblique empty roadway and the vertical stress distribution of coal pillar in the driving process of the old roadway in the old mining area are studied from the angle of 15°, 30°, 45° and 60° respectively, and the deformation law of the surrounding rock of oblique empty roadway in the driving process of the roadway in the old mining area and the distribution law of the plastic zone of the triangular coal pillar at different angles are studied. Finally, the supporting parameters for crossheading and open-off cut crossing oblique empty roadway are calculated and analyzed. The results show that the smaller the angle between the rossheading and open-off cut and the oblique empty roadway, the greater the influence on the stress distribution of the roadway surrounding rock and the triangular coal pillar. The deformation of crossheading and open-off cut roof is related to the angle between crossheading, open-off cut and oblique empty roadway. When the angle between crossheading, open-off cut and oblique empty roadway is 60°, the vertical displacement of crossheading and open-off cut roof is mainly concentrated at the junction of crossheading and oblique empty roadway. As the angle between crossheading, open-off cut and oblique empty roadway decreases gradually, the concentrated area extends to the roadway outside the junction. Due to the small angle of 15° and the narrow triangular coal pillar, the coal pillar is severely damaged under the action of vertical stress and cannot carry reasonable load. When the distance is more than 12 m from the junction, the plastic failure between triangular coal pillar is small and there is an elastic core area of more than 2 m, so the coal pillar has a good bearing capacity. The surrounding rock deformation of crossheading and open-off cut shows different rules under different support distance. The denser the support and the smaller the shed distance, the smaller the displacement of channcrossheading and open-off cut , and 800 mm is the most reasonable shed distance. The research results provide a key technology for the stability control theory and surrounding rock control of old mining area.
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