These are often used in soft soils and tight spaces, and are a common choice for river or dockside walls. They may be constructed with spaced steel or lumber piles—or may consist of continuous sheet piling, typically made of interlocking mild-steel plates. The piles are driven into the soil, typically leaving two-thirds of their length underground and one-third above the surface. The process of driving them into the ground compacts the surrounding soil, which in turn increases the strength of the pile. The piles are often anchored with a dead weight and chain, cable or rod, which must be located outside the angle of repose (in other words, beyond the potential failure plane of the soil).
Contiguous bored pile walls
These are cast-in-place ...