Is the process of using a Tunnel Boring Machine that excavates tunnels through a variety of different geologies. They can be used to bore through hard rock, sand and anything in between. A Tunnel Boring Machine has the advantage of not disturbing surrounding soil and earth. This negates the risk of soil settlement, and makes it suitable to use in well-populated areas.
- Tunnel boring machines are used to excavate tunnels through a variety of different geologies. They can be used to bore through hard rock or sand or almost anything in between.
- They can bore through anything from hard rock to sand. Tunnel diameters can range from a metre (done with micro-TBMs) to 19.25 metres to date.
- Tunnels of less than a metre or so in diameter are typically done using trenchless construction methods or horizontal directional drilling rather than TBMs.