Different types of deep foundations in construction & their applications
The role of deep foundation is to bear loads from a structure via feeble compressible soils or fills in to sturdier and less compressible soils or rocks at depth, or for operational purposes.
Deep foundations are constructed in deeper area underneath the finished ground surface toward their base bearing strength that will be influenced by the conditions of the surface, it is normally at depths >3 m under finished ground level.
Deep foundation is needed to transmit the loading to a deeper, more efficient strata at depth when unfitting soils exist adjacent to the surface.
Types of Deep Foundation - Different types of deep foundations are found for common usages :
2. Buoyancy rafts (hollow box foundations)
5. Shaft foundations
6. Pile foundations
Basement foundation: These belong to void substructures which are created to arrange working or storage space underneath ground level. The structural design is monitored with their functional needs instead of from concerns of the most effectual method of withstanding external earth and hydrostatic pressures. They are built up in position in open excavations.
Buoyancy rafts (hollow box foundations): Buoyancy rafts stand for void substructures which are created to organize a buoyant or semi-buoyant substructure underneath which the net loading on the soil is curtailed to the needed low intensity. Buoyancy rafts are created to be sunk as caissons, they are also built up in position in open excavations.
Caissons foundations: Caissons stand for void substructures which are created for being developed on or adjacent to the surface and then sunk as a single unit to their needed level.
Cylinders: Cylinders belong to small single-cell caissons.
Drilled Shaft foundations: Shaft foundations are built up inside deep excavations which are sustained by lining built up in position and consequently stuffed by concrete or other pre-fabricated load-bearing units.