Tunnel
An underground passageway.
Cut and Cover
A method of tunnel construction that involves digging a trench, building a tunnel, and then covering it with fill.
Fire-Setting
An ancient tunneling technique in which rock is heated with fire and then doused with cold water, causing the rock to fracture.
Rock Tunnel
A passage constructed through solid rock.
Soft-Ground Tunnel
A passage constructed through loose, unstable, or wet ground, requiring supports to keep the walls from collapsing.
Tunnel Boring Machine
A mechanical device that tunnels through the ground.
Tunnel Shield
A cylinder pushed ahead of tunneling equipment to provide advance support for the tunnel roof; used when tunneling in soft or unstable ground.
See also: Cut and Cover, Fire-Setting, Rock Tunnel, Soft-Ground Tunnel, Tunnel Boring Machine, Tunnel Shield.
Subjects: Civil Engineering