Which of the following is not included under preliminary survey?

Underground excavations for carrying pipes, sewage etc. fall under which type?

Pick the rock considered as soft rocks for tunnelling.

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

Type of hydropower tunnel where water is conveyed under high pressure to turbines is ______

The underground routes or passages driven through the ground without disturbing overlying soil cover are called ______

Which type of strata is rare in occurrence?

Method of placing tubes in public utility tunnels is called ______