modern world tunnels are excavated for various purposes like laying
pipes, building underground railways, mining operations, for
multipurpose hydel projects etc. Tunnel excavation requires lots of
technical skills and sophisticated machineries.
Construction of tunnels is done using materials varying from soft clay to hard rock. There are many factors on which the method of tunnel construction depends on. These are like the ground water conditions, ground conditions, the diameter and length of the tunnel drive, the tunnel depth, the logistics of supporting the tunnel excavation, and most important of all the final use and shape of the tunnel and risk management.
Usually tunnels are of three types:
- Cut and cover tunnels: These are constructed in a shallow trench. These are then covered.
- Bored tunnels: These are constructed without removing the ground above and are in circular or horseshoe cross-section.
- Immersed tube tunnels: These tunnels are floated into a body of water or are buried just under its bed.
Types of Tunnels Construction Machines
For tunnel excavation
lot of machineries are available, which are as follows :