Civil: Tunneling

Tunneling

Process of making tunnels in order to reduce distance of travel or traffic congestion for highway and railway is called tunneling.

Tunneling is important for the following purpose

o Time saving and reduction in fuel o Avoid unwanted traffic congestion o Maintain a proper speed

o Avoid tiredness of travel o Avoid unwanted accidents

o To avoid deforestation and death of animal while crossing o To avoid land slide in hilly region

o  To avoid the long route around the mountain

o  To reduce the length of highway and railway and it may be economical

o  To have flatter gradient that is essential to maintain the speed of the vehicle

Tunneling types depending upon the shapes

Poly centric

  Horse shoe

Size of the tunnel

It depends upon the number of track and the width and length of the mountain

Alignment of tunneling

o  Identify the shortest route

o Height of mountain should be less o Mark the points on the mountain

o Transfer the tunnel inside the mountain by making of required depth o Checking the tunnel cross section whether equal every where

Methods of tunneling

Shaft  tunneling

Pilot         tunneling

Shaft tunnels

Vertical passages are created along the line o the tunnel then the tunnels can be excavated by the passage of having distance half of the distance between adjacent passage openings are available to take the excavated material ,shafts can also be used to pump out the water

Pilot tunneling

If the height of the mountain is more then we can exercise this method of tunneling but uf he horizontal length is more, shaft tunneling is done