Research and practice on retaining sand-proof pillar mining in thin seam in yangcun coal mine

Based on the exact understanding of water abundance in the 3~(rd) unconsolidated aquifer and the rule of overlying strata damage in thin seam,the influence of water inrush on working face is estimated,the feasibility of retaining sand-proof pillar mining in the 2~(nd) mining area in Yangchun Colliery is demonstrated and the safety mining is realized successfully.The height of sand-proof pillar of Yangchun Colliery in thin seam is reduced from 30m to 10.42m and 6.38Mt coal under water body is able to be mined now.