In blowing led mechanical ventilation in a tunnel, the advantage is /are

i. positive supply of fresh air at working place is obtained

ii. vitiated air, smoke and dust are removed slowly

Select the most suitable method of tunnelling in rocky ground

The most popular lighting method used in tunneling operations is

Which is correct statement in case of lining of tunnels?

i. It supports the loosened rock pieces during blasting

ii. It gives proper section to the tunnel

iii. It strengthens the weak locations in the tunnel

Which of the following is/are example(s) of ‘tunnelling through soft ground’?

i. Forepoling method

ii. Needle Beam method

iii. Head and benching method

Which of the following method(s) can be used for tunnelling in soft soil?

i. Forepoling method

ii. Needle beam method

iii. Heading and benching method

The section of the tunnel adopted perfectly in lieu of ease of construction and maintenance in hard rock tunnels, where the risk of roof failure or collapse caused by external pressure from water or from loose or unstable soil conditions on tunnel lining is practically non existent, is

The Drift method of tunneling is best suited for

Which one of the following tunneling methods is used for laying underground sewers?

Resonators are used in tunnels for the purpose of