Civil Engineering - Tunnelling

Exercise :: Tunnelling - Section 1

  • Tunnelling - Section 1
21. 

Which one of the following statements is not correct in respect of setting of an inclined tunnel:

A. Reference points are constructed at every 300 m.
B. The alignment is fixed from upper/lower apex point.
C. The level of the invert at the heading is marked by a tape.
D. Reference points are constructed on the roof of tunnels
E. None the above.

Answer: Option E

Explanation:

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22. 

Forepoling method is generally adopted for tunnelling in :

A. soft ground
B. firm ground
C. running ground
D. None of these.

Answer: Option A

Explanation:

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23. 

Concrete lining is provided concurrently with the driving operation in case of

A. rock terrain
B. soft rock
C. running soil
D. none of these.

Answer: Option A

Explanation:

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24. 

The concentration of the dust particles of the size 0.5 to 5 microns adjacent to the working face should not be more than

A. 200 particles/cm3
B. 250 particles/cm3
C. 300 particles/cm3
D. 450 particles/cm3
E. 400 particles/cm3

Answer: Option D

Explanation:

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25. 

Which one of the following statements is not correct with regard to heading and hench-ing method of tunnelling.

A. Driving of tunnel is done in two portions of its section
B. Driving the top portion is done in advance of the bottom portion.
C. After driving the top portion 3 m to 3.5 m holes are drilled into the head and bench.
D. The holes in head and bench are loaded together with explosive for blasting.
E. Firing of head holes is done just before the bench holes are fired.

Answer: Option E

Explanation:

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