大断面巷道掘进
large section tunnel advance
井巷掘进
tennel excavation
Shaft and Lane Excavation
TUNNELLING
shaft digging
勘探平巷掘进技术
prospecting drifting technology
煤巷掘进面
driving face of coal roadway
岩巷掘进
rock drift driving
rock tunneling
driving rock roadway
rock drift tunneling
stone drifting
rock driving
excavation of rock laneway
deading
opening drifting
drift heading in rock
deadwork
development work in coal