补孔深度比例
Depth proportion of perforaation
超千米深孔
borehole deeper than 1000m
冲击式深孔钻机
long-hole percussive machine
大区深孔台阶爆破
large deep hole bench blasting
大直径深孔
large diameter longhole
big-deep holes
big-diameter deep-hole
deep-hole with large diameter
大直径深孔爆破
large diameter deep hole blasting