Support technology for main roadway passing through goaf in Tenghui Mine re-mining area

Abstract

In order to solve the problem of roof caving during the excavation of the roadway of Tenghui 2# coal passing through the old goaf, the research on the evolution law of the displacement field and stress field of the roof and floor during the heading face to reveal the old goaf was carried out. The stress state and affected range of the tunneling roadway at different stages during the disclosure of the old goaf were obtained by combining theoretical calculation, on-site monitoring and numerical simulation, and the support scheme of the tunneling roadway over the old goaf was determined. The calculation results show that there is a plastic area of 5-10 m at the edge of the old goaf in the coal seam, and when the roadway continues to advance towards the old goaf, the stress state of the columnar coal body between the heading face and the old goaf changes from elastic to plastic. The evolution trend of roof and floor displacement is not synchronized during roadway excavation, and the deformation rate of roof displacement increases by 20% as the roadway gets closer to the goaf, and the deformation rate of the floor gradually decreases as the heading face approaches the goaf until it reaches a stable value. The field experimental results show that the increase of the relative deformation of the top and bottom plates in 50 d is controlled at 25 mm, and the increase of the relative deformation of the two groups is controlled at 23 mm, and the deformation of the surrounding rock of the roadway is effectively controlled.

Keywords

• roof plate stability
• roadway excavation
• old goaf
• numerical simulation
• roadway supporting
• surrounding rock control