A. removal of bottom portion
B. excavation of one drift in the centre
C. removal of top portion
D. excavation being done along the periphery
Related Mcqs:
- Drift method of tunnelling is used to construct tunnels in__________________?
A. soft grounds
B. rock
C. self supporting grounds
D. broken grounds - The correct sequence of drilling equipment for increasing size of holes in tunnels is________________?
A. wagon drill, churn drill, shot drill
B. wagon drill, shot drill, churn drill
C. shot drill, churn drill, wagon drill
D. churn drill, wagon drill, shot drill - Which of the following lining material is useful for shield driven tunnels in sub aqueous regions ?
A. stone masonry
B. timber
C. cast iron
D. cement concrete - Which of the following methods of tunneling is used for long tunnels at great depths ?
A. Army method
B. Needle beam method
C. Austrian method
D. English method - Ribs are used for strengthening and stiffening the liner plate for tunnels of diameter greater than_____________________?
A. 2 m
B. 3 m
C. 4 m
D. 5 m - If ‘N’ is the number of shafts used, then the total number of feces available for attacking the excavation and construction in tunnels are_________________________?
A. 2N
B. N + 2
C. 2 N + 1
D. 2 N + 2 - Circular section of tunnels is not suitable for________________?
A. carrying water
B. non-cohesive soils
C. tunnels driven by shield method
D. placement of concrete lining - Assertion A : English method of tunneling requires more time as compared to other methods of tunneling. Reason R : In English method of tunneling, the masons and excavators have to work alternately/
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true and R is not the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true. - As compared to a single free face, if a charge of explosive is placed equidistant from two faces, then the yield___________________?
A. remains same
B. decreases
C. increases by 2.25 times
D. increases by 3.5 times - Assertion A : When rock conditions are favorable, it will not be necessary to take up concrete lining concurrently with the driving operations till the full length of the tunnel has been driven through rock. Reason R : A tunnel through rock, hard or soft, does not need any concrete lining________________?
A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true
