A deep foundation is used where the soil underneath the structure is not able to support the building load within the appropriate depth; therefore the structure has to rest at a greater depth.
The function of deep foundations is to transmit the weight of the building to firm layers deep inside the ground.
Deep foundation can be selected in the following situations:
- The hard layer of soil at greater depth.
- Loading from the structure is concentrated on heavy soils.
- Offshore construction in marshy areas.
- Where a structure is susceptible to uneven settlements.
- Deep foundations occur as pile foundations and well foundations.
Type of Deep Foundation:
The stack is defined as a tapered column capable of transferring structural loads to the underlying layers.
Uses of piles foundation:
- Piles are used to bear the vertical compressive load for better understanding.
- Vertical piles are used to carry the vertical compressive load of superstructures such as bridges, buildings, and so on.
- Piles are used for the foundation of a building to hold the load from the superstructure.
- Piles are also used to resist bending as well as horizontal forces.
- Use of piles to resist lateral loads in ease of bridge and retaining wall structures.
Well Foundation is a watertight construction ideally manufactured from wooden, steel, R.C.C.
It is constructed in reference to excavation for the foundation of bridges, piers in rivers, dock structures, and so on.
Uses of the Well Foundation:
- This foundation is more suitable for underwater foundations.
- This foundation should be spread below or above the river bottom or the ocean floor to realize proper stability.
- The Well Foundation has been built in connection with the excavation of the foundations of rivers and ponds, bridges, breakwater dock structures for the approach to rivers and ponds, ponds, deep houses, etc.
- Caissons are used as foundations for bridge piers, rivers, seas, lakes, breakers and for sanctuaries in various coast construction works.
- It can be used for home pumps that are subject to huge vertical as well as horizontal forces.
- It can be generally used for big and multi-storey buildings and different structures.
These are hollow substructures designed to operate below ground level or current storage space.
Structural design in an environmentally friendly way to resist the external environment and hydrostatic pressure is achieved by their functional requirements.
These have been built in place in open excavations.
Uses of Basement Foundation:
- Daylight basements can be used for many purposes such as the garage, maintenance room, or living space.
- The buried part is used for storage, laundry rooms, hot water tanks and HVAC.
- Daylight basement homes are usually taller than standard-basement homes, include more viable dwelling areas. Also, read advantages of deep foundation.
Hollow box foundation:
This foundation is hollow substructures designed to offer a semi-buoyant sub-structure, due to which the net loading on the soil is reduced to a lower intensity.
They can be designed to sink as caissons, they can be constructed in open excavations.
Uses of Hollow box foundation:
- This foundation is more environment friendly than pile foundations within the areas with very weak soils for large depths.
Drilling shaft foundation:
This foundation is constructed inside a deep excavation, supported by a lining built in place, then filled with concrete or other prefabricated load-bearing components.
Uses of Drilling shaft foundation:
It is largely used to help buildings with axial and lateral loads by digging cylindrical shafts into the ground and filling them with concrete.
Cylinders are small single-celled casein.
Advantages of deep foundation:
- Piles can be prefabricated off-site which allows efficient installation on the site.
- The induced piles displace and compact the soil which will increase the bearing capacity of the pile.
- Piles are durable and will keep the facility safe and strong for many years.
- Increase overall productivity.
- A pile quickly damaged by driving through stones and boulders.
- Piles can be attacked by saltwater marine bits.
- A stack cannot be above ground level.
- It is very difficult to know the actual required length in advance.
- Vibrations are produced when the piles are driving which affects neighbouring structures.
Disadvantages of deep foundation:
- Piles can undergo corrosion.
- Daily inspection required.
- Skilled labour is required to fix the piles.
Deep foundation FAQ:
Why do we use deep foundations?
A deep foundation is one that carries the load on building construction to competent soil and / or rock.
What is a deep strip foundation?
Where the strip foundation needs to be at a lower level to reach the soil with the appropriate foundation capacity, a wider, deeper trench can be dug to work
What are the types of deep foundation?
5.Hollow Box Foundations (Buoyancy Rafts)
Is code for deep foundation?
Pile Foundation Design as per IS 2911–2010.
Conclusion for Deep foundation:
Deep foundations are used to transfer structural loads to soil depth and when subjected to scour.