51.
Pick up the correct statement regarding drilling a tunnel from the following:

52.
Pick up the correct statement from the following:

56.
A tunnel is found more advantageous as compared to the alternate routes because it:

57.
The needle beam method of tunnelling
(i) Is suitable for soils in which roof can stand for few minutes without support
(ii) Is suitable for brick lining
(iii) Is suitable for concrete lining
(iv) Requires large number of trench jacks

59.
In “full face” method of constructing tunnels, the first operation relates to

60.
The following operations are generally employed for tunnelling in hard rock.
1.Removing ground water,
2.Loading holes and firing the explosive
3.Setting up and drilling
4.Grouting and lining
5.Removing muck
6.Ventilation and removing explosion dust
The correct sequence is: