Which of following statements is/are true?

A. The proportioning of a footing is more often governed by its bearing capacity

B. Friction piles are also called ‘Floating piles’

Concept:

Proportioning of footing is defined as an arrangement of a footing system in such a way that the centroid of the area in contact with the soil lies on the line of action of the resultant of the loads.

It is governed by a service load criterion to ensure equal settlement of footing for various columns.

Below is the figure for proportioning of footing (the centroids are on same line of action).

Also, Friction piles are also called as Floating piles because these piles won’t rest over hard strata hence no reaction or resistance is offered by end bearing action, it depends upon skin frictional resistance.

Important points:

For ordinary buildings:

Service load = Dead load + 0.5 × (Live load)

Skin friction: it is the resistance offered by surface area by the action of friction offered by soil granular on pile.