宣东二矿主井井筒冻结基岩段深孔光爆法施工

A construction with deep—hole smoothwall—blasting methodat freezing basement section in Xuandong 2# Mine main shaft

宣东二矿主井井筒冻结基岩段运用伞钻打眼，采用深孔光面爆破技术，全断面一次爆破方法，在施工中取得了安全、快速、优质和高效的综合技术经济效果和前所未有的实践成果。

Umbrella drills were worked at freezing basement section in Xuandong 2# Mine main shaft,deephole smoothwall—blasting technology and full—section once—through blasting method were taken to make comprehensive technical and economic results in safety、speed、quality and efficiency during its construction time and pratical gain at that time people had never had it there.