Subway and tube railways are studied under which type of tunnels?

What occurs due to falling of big rock blocks or sides due to release of stresses during tunnelling?

Which type of geological structure can be rectified by grouting?

Traffic tunnels are always constructed for kilometres.

Layers dipping at angles up to 45° may be called ______

Lithology does not affect which parameter?

Pick the rock considered as soft rocks for tunnelling.

Selection of excavation method depends on ______