Research on stability of coal pillar and roadway layout optimization in shallow multi-seams

In order to solve the problems of dfficult stress zone division and roadway layout in shallow multi- seams mining, according to the actual condition of Bul ianta Coal Mine, the stress at the bottom of upper pillar and deformation of surrounding rock in lower roadway were analyzed by theoretical analysis, field observation a nd numerical simulation. The size of coal pillar and staggered distance of extraction roadway were researched in the process of downward combined mining in shallow coal seams. The results showed that for stress areas were determined inaccurately, roadway could not completely avoid high stress areas in some cases, in a consequ ence, roadway deformation for the stress increased sharply in lower seams. By the comparison of numerical simulation, the width of lower seam pillar adopted 26 m, it was44% larger than former data, stagger distance of roadway adopted 32 m, the deformation of floor and two sides in the roadway were reduced obviously.