Drilled piers and caissons are primarily used for foundation support, utility support, tower support and light pole bases.
Drilled piers and caissons are constructed by utilizing a drill rig equipped with an auger. The drill rig drills a specified diameter hole vertically into the soil and/or rock, to a specified bearing elevation. Steel reinforcing is placed in the hole and the hole is filled with concrete. This is a simplistic example. Often, though, other tooling is required to successfully complete a drilled pier or caisson.
In addition to a dirt or rock auger, core barrels, and clean-out buckets are required. Temporary or permanent casing may be required if soils are granular and/or wet. Sometimes slurry is required in order to maintain a stable hole and concrete has to be placed utilizing a tremie system.
