Need for use of piles foundation and types of pile foundation

Pile foundation is used to transfer the weight of the building or structure deep in the ground for giving more stability to the structure. A pile is a vertical structure of the pile foundation, which is driven deep into the ground at the building site. Under the normal soil conditions, the pile resists the vertical uplifts and horizontal loads. That is why they are used to support heavy load of tall building, bridge abutments etc.

The need for pile foundation comes when the upper layer of the soil is very weak and this layer cannot support the weight of the building to be constructed on the soil. The pile is then pushed into the ground to bypass the weaker layers and get to the strong layer deep in ground. Pile foundation is also imperative when over land structure has heavy load like high rising building or bridge or water tank

Types of pile foundation –

End bearing piles and friction piles

In the end bearing piles, pile foundation the bottom part of the pile is rested on the strong layer or on some rock for support of the bulling. The weight of the entire building is then on the pile which is resting on the strong foundation. This pile is inserted deep enough to bypass the weaker layers of the soil and go into strong layers. The length to which end bearing pile will go will depend on the soil investigation and soil testing by engineers.

Friction pile works by different method. Friction pile spreads the weight of the building to the soil by friction method. The load supported by a friction pile is directly proportional to its length in the ground.

Since piles are carrying lot of load, they are designed very carefully. The engineers first study the soil; the piles are inserted in, to ensure that the weight which is placed on the soil is within its carrying capacity. Every pile which is inserted into the soil has an influence area around it. The other pile should be placed outside its influence area. This kind of placement is done to distribute the weight of the building over the entire soil rather than allow it to concentrate in narrow area. 

Engineers geotechnical services also put several piles together and then put a cap on them to unit them. This cap is made from concrete and provides a base over the several piles. This base is then use for erecting Column of the building. This weight of the column is distributed over the piles underneath.