Piles can be classified into many types based on their load transfer mechanism.
- Friction piles
- Bearing piles
- Friction-cum-bearing piles.
- Guide piles
- Batter piles
- sheet piles.
Bearing piles are ground-driven piles supported on a hard stratum. They act as pillars or columns allowing the vertical loads to be transferred from the foundations to underneath deep strata. They resist load by the bearing capacity of the column.
Unlike bearing piles, which resist load by developing bearing action in the columns, friction piles resist loads by developing the frictional forces along the pile surface. The longer the length of the pile more is the amount of load it can resist.
Similarly, the greater the area more it can resist. Frictional force generated in these piles is a function of pile surface area.
To increase the load-bearing capacity of piles there surface area should be increased. The type of material also plays an important role in increasing the amount of frictional force. Rough surfaces offer good frictional resistance.
These piles are not required to rest on hard strata.
Friction cum bearing piles
These types of piles resist the axial loads through both actions bearing and frictional forces.
In reality, you will find most of the piles of this nature, which would be designed to resist by developing both of these resistive forces.
In contrast to the previous two types of piles, which are used to resist action in the vertical direction, batter piles resist seismic forces by their diagonal placement.
As a result, the horizontal component of the internal resistive force developed in the battered pile resists the horizontal external load. The internal force developed in batter piles can be due to both the friction component and the bearing component or either of one.
These are a special type of piles used in the formation of the cofferdam to perform stabilization for any submerged water construction.
Piles can also be categorized based on the type of material. Following are the most common type of piles based on material differences.
- Concrete piles
- Steel pipes
- Timber piles
- Steel H or I shaped piles
- Composite piles