Which one of the following tunnelling methods is used for laying under ground sewers ?

A good blast with a good yield is obtained if the cut hole is___________________?

A. normal to face

B. inclined at 45° to the face

C. inclined at 15° to the face

D. inclined at 30° to the face

Drifters can be used to drill_________________?

A. only up holes

B. only down holes

C. horizontal or up holes

D. horizor„al, down or up holes

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

In compressed air tunneling, the volume of free air provided is______________?

A. 6 mJ per second per m2 of face area

B. 6 m3 per minute per m2 of face area

C. 20 m3 per minute per m2 of face area

D. 6 m3 per hour per m2 of face area

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