Drilled Shafts (Caissons)

By October 24, 2014 No Comments
Drilled shafts (caissons), drilled piers or bored piles, are often the deep foundations deep foundations of choice for buildings with high or concentrated column loads. Construction can be by the dry, wet or cased method, depending on the subsurface conditions and groundwater table elevation. Dry shaft construction, as the name implies, relies on the soil/rock to be self-supporting during excavation, reinforcement placement and concreting. Wet construction involves the use of a slurry to maintain hole stability during excavation and completion of the shaft element. Temporary casing is often used where the soils are dry, but their characteristics are such that caving or sloughing is anticipated during excavation, or where clean granular soils are present below the water table and the shaft must be seated into an impermeable layer to prevent water flow into the borehole. Read more.