Deep Foundations
Foundations whose depth is more than their width are referred to as deep foundations for a building or structure. Typically, when a depth of more than 3m is to be achieved, deep foundations are laid to provide the required strength and stability to the structure being built by providing a solid platform for construction. Thus, these foundations act as strong anchors for the buildings.
Deep foundations play an important role in carrying out construction work in unstable ground conditions where loose soil cannot withstand the weight of a building. In such conditions, deep foundations make the ground surface stable by transferring and ensuring even load distribution to greater depths where ground conditions are relatively stable.
This guide provides you with information about deep foundations, their uses, types, advantages, and disadvantages.
Uses of Deep Foundations
Deep foundations are extensively used in unstable ground conditions to provide the required support to the structures being built. They are used for tall buildings, such as skyscrapers, to provide the necessary support to bear the height and weight of these structures and prevent instability or settling over time.
Deep foundations are laid for the formation of bridges and overpasses to bear the load efficiently and deal with the dynamic forces that come with vehicular loads. These are also used for constructing industrial facilities in which heavy machinery and large equipment are present, handling significant loads and preventing ground settlement problems.
Moreover, deep foundations are also found in historical buildings and monuments, which ensure that their structure stability is maintained for a longer period without settling.
Types of Deep Foundations
The following are some of the types of deep foundations:
Basements
Basements are hollow sub-structures which are constructed in different domestic and commercial buildings which require additional space to be used for various purposes. Basements can be used as living or storage spaces in residential properties and as parking garages in commercial properties. These can be constructed by using concrete blocks, poured concrete, or wood framing methods based on the load requirements.
Buoyancy Rafts
Buoyancy rafts are hollow box foundations that float under the ground level and are suitable for constructing a building or structure in weak soil conditions. For constructing buoyancy raft foundations, the soil is removed to create a hollow space where foundations are laid. These foundations then conveniently carry the weight of the structure reliably.
Caissons
Caisson foundations are cylindrical and hollow substructures sunken below the ground surface at a certain depth. They are laid in soils with stable strata in deeper layers and weaker upper layers. These types of foundations are mostly used for constructing structures such as bridges and piers in water environments.
Diaphragm Walls
These foundations act as retaining walls and have multiple vertical panels formed one after the other. A special type of bentonite slurry is used during the excavation to prevent the deep trench walls from caving in. These deeper foundations allow for effective above-ground and sub-ground construction.
Drilled Shafts
Drilled shafts have concrete pillars for which the holes are drilled into the ground into which reinforced steel is added and concrete is poured to fill the holes, providing the necessary support. This process results in the formation of strong and sturdy foundations that help in even weight distribution between the foundations and the structure being constructed.
Pile Foundations
For the formation of pile foundations, hollow tubes are filled with concrete and connected together with grade beams. These foundations ensure even weight distributions and provide structural support to the building. The piles provide a solid and stable base and are strong enough to bear the weight of the entire structure.
Advantages of Deep Foundations
The following are some of the advantages of deep foundations:
- The simple and quick installation process saves you a lot of time.
- Deep foundations ensure the safety, stability, and reliability of a particular structure.
- The process of deep foundation installation is cost-effective as it requires fewer resources.
- These foundations can be pre-fabricated off-site, which allows for easy and efficient installation.
- These are helpful in making the structures long-lasting, as strong materials, such as concrete, are used in their construction.
- These can be conveniently used for constructing heavy and large structures, providing a solid base and stable ground surface.
Disadvantages of Deep Foundations
The following are some of the disadvantages of deep foundations:
- The vibrations produced during the rigs’ installation can impact the new foundations or neighbouring structures.
- The varying weather conditions can negatively affect the concrete hardening process, which can make it difficult to complete the project timely.
- The laying of deep foundations for heavy and large structures requires undertaking extensive preparation, research, and planning to ensure ultimate success.
- These foundations can be damaged by corrosion caused by natural forces, rocks, or water, which negatively impacts the building structure’s stability and integrity.
Final Words
Deep foundations are used for completing large-scale and complex projects for the construction of heavy structures. These are extremely helpful for constructing buildings and different structures on difficult ground conditions as they help to make the base solid and stable for efficiently supporting the load of structures being built.
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