Abstract: The research in this paper was conducted based on realizing inclined sufficient and successive pressure-relief in lower protected coal seam mining. The results show that due to the length of coal face, interval between layers, borderline of pressure-relief and coal pillar layout, the pressure-relief in the inclination of the distant protected coal seam can’t be realized, and the high stress zones or insufficient pressure-relief zones may exist in the close protected seam. The safe and successive mining of protected seam can’t be realized. On this basis, the pillarless face layout in protected seam was proposed. Thus, the overlying strata movement during the successive face mining may integrate with that of the first mining face, the inclined successive mining length can be enlarged, and the mining degree of the overburden strata is more sufficient. So, the horizon of the protected seam in the fractured zone is relatively lower, which means the pressure- relief degree is more sufficient. Hence the inclined successive and complete pressure-relief in the protected coal seam can be realized. Combined with the practical engineering conditions in one mine, taking recovery ratio and engineering amount of roadway into consideration, the profit of No.2 Coal Seam mining when adopting pillarless mining is increased by 284 million yuan compared with the original mining plan. Morevoer, compared with the roadway driving along the goaf remaining 5-metre pillar, the engineering expense of rock roadway can be reduced by 6 million, and the mining profit can be increased by 140 million.

Key words: outburst coal seam；pressure relief；lower protective seam；coal pillar；&ldquo, three zones&rdquo