15.  Which one of the following methods is generally adopted for tunnelling in firm ground
A. Full face method
B. Top heading and benching method
C. Drift method
D. All the above.

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16.  For full face method, the excavation to be done is generally divided into
A. two sections
B. three sections.
C. four sections
D. five sections

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17. Forepoling method is generally adopted for tunnelling in :
A. soft ground
B. firm ground
C. running ground
D. None of these.

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18. Railway tunnels, are generally
A. polycentric
B. rectangular
C. parabolic
D. circular

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19. In case of drift method of tunnelling, the drift may be excavated at
A. the centre
B. the bottom
C. the top
D. All of the above.

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20. 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 :
A. 3,2,6,5,1,4
B.3,4,6,1,5,2
C. 4,1,2,3,6,5
D. 5,4,2,1,3,6.

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21. Which one of the following methods of tunnelling doe not require the use of time bearing :
A. Linear plate method
B. Shield method
C. Compressed air method
D. All the these.

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