Application of Pier Column Gob-side Entry Retaining Roadway in Weak Roof Coal Seam

In order to improve the recovery rate of coal seam in the thin roof of Dongda Coal Mine and extend the mining time of the mining area, the feasibility of the application of pier column gob-side entry retaining technology in the mine is demonstrated from the theoretical and numerical simulation. During the period of gob-side entry retaining, vertical stress distribution characteristics, horizontal and vertical displacement characteristics are analyzed. The engineering practice shows that the pier can provide a large support resistance, which can effectively cut off the roadway stress transmission path, reduce the roadway pressure, improve the utilization rate of coal resources, and provide the engineering examples for the thin coal seam mining design.