Study on long-term stability of strip coal (rock) pillar by replacement mining in short-distance thin coal seam

The strip replacement mining in short-distance thin coal seam is one of the effective methods controlling displacement deformation of overlying strata and surface subsidence in coal mining under buildings and railroads and water bodies. The method has a great theoretical significance and application value by increasing recovery rate of coal resources and cutting down the effect of coal mining on environment and surface of mining area. The numerical simulation and field test methods are adopted to study long-term stability of coal (rock) pillar by strip replacement mining in short-distance thin coal seam. We find that the strip replacement mining technology is verified to be feasible; ten meters in replacement width of coal pillar is relatively optimum, and can presents long-term stability of strip coal (rock) pillar. Therefore, the strip replacement mining technology has provided a new thought to coal mining under buildings and railroads and water bodies.