隧洞灌浆施工技术
tunnel grouting construction technology
隧洞掘进机
Tunnel boring machine TBM
coal mine area in the western China
隧洞开挖
tunnel excavation
excavation of tunnel
underground tunnel excavation
tunneling
tu nnel excavation
隧洞开挖计算
calculation of tunnel excavation
隧洞摄影编录
photographic description of tunnel
水工隧洞
hydraulic tunnel
hydraulic engineering tunnel
Hydro-power tunnel
water tunnel
power tunnels
Water diversion tunnels
precast concrete segment