Optimal layout of roadway under goaf of shallow coal seam group in Donggou Coal Mine

Abstract

In order to study the roadway layout and reasonable staggered distance of the lower coal seam during the mining of short-range shallow coal seam, taking Xinjiang Donggou Coal Mine as the engineering background, the simulation of the layout of internal, external and vertical staggered layers is carried out by using FLAC3D numerical simulation method, and the influence of residual coal pillar on the stress distribution of the lower coal seam after the mining of the upper coal seam is compared and analyzed, as well as the distribution law of vertical stress and plastic zone under different staggered distance. The results show that: considering the influence of residual coal pillar floor stress propagation in the upper coal seam, when the mining roadway of B3 coal seam adopts vertical staggered and internal staggered distance of 4-16 m, the mining pressure of the lower roadway can be reduced and excessive deformation of the roadway can be avoided; considering the factors of stress distribution, plastic deformation and economic benefit, the vertical staggered time in B3 coal seam can ensure the stability of roadway, and the recovery rate and economic benefit are the highest, which is the best scheme; the engineering measurement results show that under the vertical staggered arrangement, the approach of the two sides of the roadway is 23-185 mm, and the approach of the roof and floor is only 12-85 mm.

Keywords

• shallow coal seam group
• staggered horizon mining
• roadway layout
• stress distribution law
• surrounding rock support