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Load transfer mechanism for piles

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piles are used for a structure that supporting large loads such as bridges and skyscrapers and in the case, if the soil that supporting the structure is weak and the bearing capacity is low. pile transmits the loads to the soil through two mechanisms:

  • Friction pile: piles develop most of the pile-bearing capacity by shear stresses along the sides of the pile, and are suitable where harder layers are too deep to reach economically. The pile transmits the load to surrounding soil by adhesion or friction between the surface of the pile and soil, the whole surface of the pile (cylindrical in shape) works to transfer the forces to the soil.

 
Figure 1


  • End bearing pile: End-bearing piles develop most of their load-bearing capacity at the toe of the pile, bearing on a hard layer of rock or very dense soil and gravel. The pile transmits the load through soft, compressible strata directly onto firm strata. This type of pile, therefore, acts in the same way as a column.




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