sprung blasthole是什么意思

网络释义

1)sprung blasthole,扩孔底炮眼2)Hole-springing hole,扩底炮孔3)blast-hole springing,炮眼底扩大4)point,炮眼底5)bottom perforation,底部炮眼6)perforations,炮眼(射孔)