Deep foundations are needed to transfer loads from weak compressible soils to stronger and less compressible soils or rocks at depth, or for functional reasons. In general, deep foundations are placed too deep below the ground surface to be affected by surface conditions, usually at depths greater than 3 meters. A deep foundation can be used to transfer loading to deeper, more competent strata at depth when the soils near the surface are unsuitable. Some techniques used in deep foundations are cased drilled shafts, drilled shafts (bored piles or caissons), Omega piles (drilled displacement piles), CFA Piles (auger cast, augered cast-in-place piles [ACIP] or auger pressure grouted piles [APG]), Micropiles and Tiedowns anchors.
Micropiles are small diameter (usually less than 12 inch diameter) drilled and grouted foundation elements with design loads ranging from 50 to 400 tons. The structural load is principally carried in steel reinforcement and transferred by friction into surrounding ground.…
Continuous flight auger piles (CFA piles) are also commonly called augercast, augered cast in place piles (ACIP) or auger pressure grouted piles (APG). They are predominantly used in unstable soil conditions with a high ground water level when conventional drilling…
OMEGA piles are a full displacement cast In-situ pile system developed in Belgium in 1998. The unique drilling tool allows the lateral displacement of the soil during pile installation. This method increases the lateral stresses in the surrounding soil, enhancing…
Drilled Shafts (also known as bored piles or caissons) have been used as deep foundations load bearing elements for over 100 years. They have been developed for the transfer of high loads and as a vibration less alternative to driven…
Cased Drilled Shafts are required when ground conditions are so unstable that drilled holes cannot safely be stabilized with drilling slurry or where loss of ground must be controlled. Casing can be temporary or permanent steel pipe which provides a…