Which one of the following is considered to be an advantage of the heading and benching method of tunnel construction?

A. It is suitable for construction in unstable rocks
B. In this method, it is easy to install timber support
C. Tunnelling can be continuous and the work can be expedited
D. In case of excessive water, it is easy to take correct steps
✅ The correct answer is option C.

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
✅ The correct answer is option C.

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.
✅ The correct answer is option A.