of a tunneling machine is a protective structure for excavating tunnels.
With circular cross sections it makes the tunneling easy and simpler and
supported the weight of the surrounding soils without any problem. The
choice of a single or double shielded tunnel boring machine depends on
the type of geology and the excavation speed required.
It is the geology that decides about the types of the shields to be
used. Single shield tunnel boring machines are preferred machine for
tunneling soils or hard rocks. It is less expensive and is very
effective tunneling machine. Behind shield there is a rotating cutting
wheel, chamber and hydraulic jacks which helps in the process of
excavation of tunnels.
Single shield tunneling machines are used for boring earth or rocks for
making tunnels for purposes like :
- Laying underground cables.
- Tunneling for the purpose of laying tracks for underground
transportation like railways.
- For the purpose of mining.
- For laying huge pipes for various municipal operations etc.