Foundations provide support to the structure, transfers the loads from the structure to the soil. But the layer at which the foundation transfers the load shall have an adequate bearing capacity and suitable settlement characteristics. So it's important to know when and why Piling is done. Let me take you through it

1. PILE
FOUNDATIONS

2. WHY PILE FOUNDATION ?
A pile is basically a long cylinder of a strong material such as concrete that is pushed into
the ground to act as a steady support for structures built on top of it.
Benefits of Pile foundations are :
 To transmit the loads coming over it safely to the ground. The transmission is performed whether it
is vertical or horizontal or inclined loads.
 The pile foundation can be constructed in cohesionless soil by undergoing techniques of
displacement and vibration methods.
 Pile foundation helps in reducing the settlement.
 The pile foundation helps to increase the factor of safety of heavy load structures or buildings.
 The pile foundation guarantees the vertical structures above with safety, security, and reliability.
 The pile and pile cap arrangement in pile foundation help the load distribution to be performed in a
uniform manner.

3. WHEN PILE FOUNDATION ?
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,
▪ The loads of the building have to bypass this layer and to 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,
bridge, or water tank.
3) In areas where settlement issues are common due to soil liquefaction or water table
issues

4. WHEN PILE FOUNDATION ?
4) Structures might be subjected to horizontal forces that will bring
effect to the foundation.
▪ Pile foundation help in resisting this bending action along with supporting
the vertical load coming over the foundation.
▪ Hence pile foundation used in earth water retaining structures and
building structures highly subjected to lateral (earthquake and wind)
forces.
5) To resist the uplift forces created due to water table rise or any
other cause.
 Uplift forces are more common in the construction of transmission towers
and off-shore platforms. These structures will need pile foundations.

5. WHEN PILE FOUNDATION ?
6) Presence of Expansive Soil.
 Expansive soils swell and shrink as their moisture content increases and
decreases, and the pressure of the swelling can be considerable.
 If shallow foundations are used in such circumstances, the structure may
suffer considerable damage.
 When the moisture content of these soils increases, their structures may
break down.
 A sudden decrease in the void ratio of soil induces large settlements of
structures supported by shallow foundations.
 In such cases, pile foundations may be used in which the piles are extended
into stable soil layers beyond the zone where moisture will change.
7) Soil Erosion