When pile foundation is used?

It depends upon site condition, if we are willing to build a strucure at the river edge for that we drill the investigation borehole and check the strata on site if it is soil then we do standard penetration and cone penetration test in order to find out  bearing capasity and we also send some representative samles to laboratory for further test i-e Atterberg Limit. And onthe bases of these result we design the pile foundation.

And simply, pile foundation is for deep foundation.

Pile foundations are recommended when the soil is very soft with low bearing capacity and high long term settlemnt values. 

Pile foundation is also recommended when there is very low settlement requirements are set by vendors for Heavy and high speed Compressor.

Weak soil, low bearing capacity of soil.

Filling up project site

Heavily loaded structure

Space restriction pf placing foundations

Avoid settlement of foundation

Project site prone to liquefaction of soil

Pile foundation used in generallt case when supporting grounds is situated to deep, more than 6-8 m from day surface.

Pile foundations are used in the following situations:

1. When there is a layer of weak soil at the surface. This layer cannot support the weight of the building, so the loads of the building have to bypass this layer and be transferred to the layer of stronger soil or rock that is below the weak layer.
2. When a building has very heavy, concentrated loads, such as in a high rise structure.