9.4.7 Piles

Piles are long and relatively slender columns positioned vertically in the ground or at an angle and are used to transfer load to a more stable substratum. These are often used to support or stabilize structures built in geologically unstable areas mainly civil construction. The effectiveness of piles is increased dramatically when they are incorporated into an anchored stabilization system. In addition, piles are used to minimize the effects of scour and undercutting along the foundations of waterfront structures. They are either driven into the ground or are placed in drilled holes. Piles placed in drilled holes directly support the weight of a structure. Driven piles are installed in soft or loosely consolidated material and often do not directly absorb the load of a structure. Rather, the bearing capacity and stability of the soil increases as the soil surrounding the piles densifies due to a decrease in void ratio equivalent to the volume of soil displaced by a driven pile.