顺层定向长钻孔预抽瓦斯区域防突技术在特大型突出矿井中的应用
순층정향장찬공예추와사구역방돌기술재특대형돌출광정중적응용
Application of Regional Outburst-prevention Technology by Gas Pre-drainage with Bedding Directional Long Holes in Extra-large Outbust Mine