The bottom plug is designed in _____ shape.

Excavation of soil inside the well in river beds can be done by ____

For alluvial soil, the normal scour depth can be calculated by _______ formula.

For loose sand, the value of skin friction is between ____

Which of the following caissons, permits excavation in dry?

___________ forms the most common type of deep foundation for bridges.

The essential feature of a pneumatic caissons are ______

The selection of the depth of a well is based on which of the following criteria?