| Term | Definition |
|---|---|
| Mole |
A tunnel-boring machine (TBM)
|
| Monolitic lining |
A tunnel lining that is cast in place and continuous.
|
| Muck |
Excavated soil or rock that must be removed from the tunnel or shaft in order to continue advancing. The removal operation is termed "mucking" or "mucking out".
|
| Muck removal |
The process of loading and transportation of the excavated ground from the face to the point of disposal.
|
| Mucker |
Machine for loading excavated material into haulage units.
|
| Mucking (out) |
See Muck removal
|
| Mucking machine |
Any type of equipment used to load muck at the tunnel face.
|
| Mudsill |
Continuous horizontal member installed along the side of a tunnel at the lowest excavation line to support sets or take the load of the supports from the wall plate.
|
| Multi / Multiple drift |
Excavation of a tunnel by driving two small drifts along each side of the tunnel, which allow the side support to be placed. A top drift is then and widened out slowly to take the roof support.
|
