Abstract:
Construction of tunnels or tunneling works for underground construction such as Hydro Electric power station, water conveyance, subway, etc. are required for water resources development projects. These need accelerated pace of construction.
Tunneling works and cavern excavation generally use drilling and blasting methods. Conventional methods of tunneling generally comprise of drilling and blasting, rock bolting (anchoring), wire meshing, shotcrete, grouting and lining. Conventional methods of tunneling are slow and need long time to complete the work.
The modern tunneling usually deploys equipment such as Tunnel Boring Machine (TBM), so that time-period for construction can be faster than conventional method. The modern tunneling technique is being widely used in U.S.A and Europe in all type of geological formation and for all diameters (2 to 12 meter) of tunnels. They use the tunnel-boring machine. There are however advantages and disadvantages of using conventional and modern techniques, depending on condition of rock, time-period available and budget of the project.
For the design method of construction tunnel, has to be considered depending on type of rock, geological condition, size and shape of tunnel. In this way an economical estimate of cost may be developed
