Types of piles generally found in construction

On the basis of load transfer and functional behavior, the piles are categorized as follow :-

1. End bearing piles (point bearing piles) 2. Friction piles (cohesion piles) 3. Combination of friction and cohesion piles

End bearing piles: These piles deliver their load on to a rigid stratum that is situated at a substantial depth under the base of the structure and they obtain most of their carrying strength from the penetration resistance of the soil at the foot of the pile.

The pile functions as an ordinary column and should be designed in its current manner. Even in substandard soil a pile will not collapse by buckling and this effect is taken into consideration when section of the pile is unsupported, that means if it is in either air or water.

Load is delivered to the soil through friction or cohesion. But occasionally, the soil that encircles the pile may comply with the surface of the pile and produces “Negative Skin Friction” on the pile. It, often influence the strength of the pile significantly. Negative skin friction occurs with the seepage of the ground water and compression of the soil.

Friction Piles: Under these types of piles, the load on pile is primarily countered by skin/friction resistance along the side of the pile (pile shaft). The friction piles are very effective for the soils with no cohesion like sands of medium to low density, since they can enhance the density as well as the shear strength.

If there is no layer of rock or rocklike material at a sensible depth at a site, point/end bearing piles become very long and too expensive. The piles are arranged through the softer material to fixed depth toward this type of subsoil condition.

Timber piles: Timber piles are formed with tree trunks pushed with small end as a point
Maximums length: 35m; optimum length: 9 – 20m

Max load for usual conditions: 450kN; optimum load range = 80 – 240kN

Benefits: Preliminary set up cost is significantly low, permanently submerged piles have strong resistance capacity against decay, easy to use, mostly effective for friction piles in granular material.

To get more information on other types of piles, go through the following link civilsnapshot.com