Concrete Piles

End-bearing piles gain most of their support strength through the contact of each pile tip with a sub-grade rock or soil that has a high enough soil bearing pressure to collectively support the structure at the pile tips. Both skin friction and end-bearing forces exist to some extent for any pile, adding up to provide their total support strength.  Piles, including concrete piles, are always designed to complement adjacent piles and therefore pile foundations act as a system of individual members.

Concrete piles may be either cast-in-place or pre-cast. Cast-in-place concrete piles may be installed as either cased or uncased piles. With cased cast-in-place piles, concrete is placed within a metal casing or pipe that remains in the ground and has been previously driven or installed to the proper final tip elevation. Uncased cast-in-place piles employ a similar technique, except that the sub-grade soils serve as the formwork in an open hole of the proper dimensions which has previously been drilled to the proper final tip elevation. Precast concrete piles arrive at the project site fully cured, and are then typically driven to their required depth with a pile hammer. Pre-cast concrete piles are usually reinforced with reinforcing steel and may also be pre-stressed to account for any anticipated structural loads during placement or their service life.

See also: Driven Piles vs. Jetted Piles - A Comparison