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Write short notes on Bearing pile and friction pile


Friction piles: These are piles which derive carrying capacity from skin friction or adhesion between the pile surface and surrounding soil. In other words, the entire surface of the pile, which is cylindrical in shape, works to transfer the forces to the soil. It is used to deep beds of clay and silt where deep hard stratum is very great. They do not reach to the hard stratum.
 
Bearing Piles: Piles which transfer structural load to a hard and relatively incompressible stratum such as rock or dense sand are known as bearing piles. These piles derive the required bearing capacity from end bearing at tip of the pile. The bottom end of the pile rests on a layer of especially strong soil or rock. The key principle is that the bottom end rests on the surface which is the intersection of a weak and strong layer. The load therefore bypasses the weak layer and is Safely transferred to the strong layer.
 
 

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