A pile foundation is a type of deep foundation used to transfer the load of a structure to deeper, stronger soil or rock layers when the surface soil is too weak to support the structure safely.
What is a Pile?
A pile is a long, slender structural member made of materials such as:
Concrete
Steel
Timber
Composite materials
Piles are driven, drilled, or cast into the ground.
Functions of Pile Foundations
Transfer building loads to stronger soil or bedrock.
Reduce settlement of structures.
Resist uplift forces and lateral loads.
Support structures built on weak, waterlogged, or expansive soils.
Types of Pile Foundations
1. Based on Load Transfer
a) End-Bearing Piles
Transfer load through the pile tip to a hard stratum.
Similar to a column resting on rock.
b) Friction Piles
Transfer load through skin friction between the pile surface and surrounding soil.
Used when a hard layer is not available at reasonable depth.
2. Based on Construction Method
a) Driven Piles
Precast and hammered into the ground.
b) Bored (Drilled) Piles
Holes are drilled and then filled with reinforced concrete.
c) Cast-in-Situ Piles
Constructed directly at the site within a drilled hole.
Advantages
Suitable for weak surface soils.
Can carry heavy loads.
Effective in waterlogged areas.
Minimizes settlement.
Useful for bridges, high-rise buildings, and marine structures.
