In pile foundation, a thin member made of steel, concrete or wood is inserted into the poor ground (Soil having low bearing capacity) for transferring the load of a superstructure. The load can be transmitted to a strong soil layer by friction or by bearing.
Purpose Of Pile Foundation:
1. The main purpose of a pile foundation is to transfer the loads into a strong stratum.
2. Generally, pile foundations are used when the bearing capacity of soil is very low and the structural load is heavy.
3. Compressible soil and waterlogged soil is ideal for this type of foundations.
4. Piles are mostly suitable for the foundation of high-rise buildings, bridges, piers, docks etc.
Classification Of Pile Foundation:
Depending upon the function, material and method of installation pile foundation can be further classified into following categories;
Classification Depending Upon The Function Of Piles:
1. Bearing Piles:
Bearing piles are the pile that is driven through a soft soil until it reaches to a stronger base. These piles are used as piers to support the superstructure and to transmit the load into a safe stratum.
2. Friction Piles:
When piles are compelled through a soft and weak soil by developing friction between surrounding earth and outside of the pile, it is known as friction pile.
3. Sheet piles:
These piles are used on a rare occasion like retaining wall construction. It helps to minimize the lateral subsidence of retaining soil.
4. Anchor Piles:
This pile opposes the horizontal pull by providing anchorage slip.
5. Batter Piles:
Batter piles are used to prevent horizontal and inclined forces.
6. Fender Piles:
When ships are bounded at the deck, the concrete deck being damaged. This injury of concrete deck is protected by fender piles.
7. Compaction Piles:
Compaction piles are used to increase the bearing capacity of granular soil.
Classification Depending Upon The Materials Of Piles:
- Timber piles.
- Concrete Piles.
- Steel Piles.