21. High pressure grouting is generally restored for concreting in the lining if the rock strata is:
22. The cut of a tunnel face is shown in given figure. This is called
23. The following operations are required for tunnelling in rocky terrain:
1.Removing the foul gases
2.Marking the tunnel profile
3.Setting up and drilling
4.Checking misfire
5.Mucking
The correct sequence is:
1.Removing the foul gases
2.Marking the tunnel profile
3.Setting up and drilling
4.Checking misfire
5.Mucking
The correct sequence is: