Civil Engineering - Tunnelling - Discussion

Discussion Forum : Tunnelling - Section 1 (Q.No. 27)

Tunnelling

27.

For transferring the tunnel alignment through shafts, we adopt the following steps :
1. Hanging two or more plumb lines in the shaft
2. Determining the bearing of the plumb lines i.e. plumb plane
3. Suspending a 35 kg weight by each plumb line
4. Immersing the weights of both the plumb lines in the buckets containing water.
The correct sequence of steps is :

1 2 3 4

4 3 2 1

l 3 2 4

2 1 4 3