The piles are classified as follows:
1) Classification based on the function
The piles based upon the function or use may be classified as follows:
a) Bearing Piles: The piles which do not support the load by themselves, but act as a medium to transmit the load from the foundation to the resisting sub-stratum are known as bearing piles.
b) Friction Piles: The piles which are driven in the type of soil whose strength does not increase with depth or where rate of increase in strength with depth is very slow, are known as friction piles.
c) Compaction Piles: The piles which are driven in granular soil with the aim of increasing the bearing capacity of the soil, are known as compaction piles.
d) Batter Piles: The piles which are driven at an inclination to resist large horizontal or inclined force, are known as batter piles.
e) Fender Pile: The piles used to protect concrete deck or other water front structures from the abrasion or impact are called fender piles.
f) Sheet piles: These piles are commonly used as bulk heads or as impervious cut off to reduce seepage and uplift under hydraulic structures. These piles are not meant for carrying any vertical load. The sheet piles are made of wood, steel or concrete.
2) Classification based on materials and composition
The piles based on the materials and composition are as follows:
a) Concrete Piles: They are made up of concrete and can be precast or cast-in-situ.
b) Steel Piles: A steel pipe can be rolled section, a fabricated shape or a piece of sheet pole.
c) Timber Piles: The timber piles are generally square or circular in cross section, having cast iron show at the bottom.
d) Composite Piles: The composite pile is made of two portions of two different materials driven on above the other. The two materials can be steel, timber or concrete.
e) Screw Piles: This is made of a hollow cast iron or steel shaft. The external diameter of the shaft may vary from 150 to 300 mm , which mat terminate into a helix or screw base at its base.
f) Disc Pile: A disc pile consists of hollow cast iron pipe with a disc or casing of enlarged size at the bottom, to enlarge area to very great extent. The diameter of dics pile may vary from 0.6 to 1.2m.