Pile foundations are deep foundations which are formed by long, slender, columnar elements typically made from steel or reinforced concrete, or sometimes timber.Pile foundations are principally used for large structures and in situations where the soil at shallow depth is not suitable to resist excessive settlement, resist uplift, etc.
These foundations assist in transferring the loads from superstructures, through weak, compressible strata or water onto stronger, more compact, less compressible and stiffer soil or rock at depth, increasing the effective size of a foundation and resisting horizontal loads.