As the name suggests, a deep foundation is a type of foundation that is continued in deeper depth to support the stability of the structure.
Let’s dive in to know more deeply about them!
Types of Foundations
Foundations come in two main categories: shallow foundations and deep foundations.
- Shallow foundation: These foundations rest on the upper layers of soil, typically within 3 meters (10 feet) of the surface.
- Deep foundation: Deep foundations, on the other hand, reach down to deeper, more stable soil layers or even bedrock.
What is a Deep Foundation?
Deep foundations are usually dug deeper into the soil layers. This type of foundation dives much deeper – typically with a depth exceeding their width by a factor of 4 or 5.
They transfer the structure’s weight down to these lower, stronger layers, ensuring stability and preventing settling or collapse.
Types of Deep Foundations
Deep foundations come in various forms, each with its own strengths and applications:
- Pile Foundations: Slender, long columns driven, drilled, or vibrated into the ground, transferring the load through friction or bearing on the lower tip.
- Caisson or Well Foundations: Large, pre-fabricated boxes sunk into the ground, ideal for deep excavations and providing a watertight work environment.
- Basement Foundation: Essentially a deep, enclosed excavation that becomes an integral part of the structure, offering additional usable space.
- Buoyancy Raft: A waterproofed foundation that floats on a layer of groundwater, used for structures built on very soft soil or water.
- Shaft Foundations: Deep, wide excavations with reinforced concrete walls, suitable for situations requiring significant lateral load resistance.
Advantages of Deep Foundations
- Increased Load Capacity: They can support much heavier loads compared to shallow foundations.
- Improved Stability: They provide superior stability in weak or uneven soil conditions.
- Reduced Settlement: Deep foundations minimize the risk of a structure settling over time.
- Accommodate Expansive Soils: They are ideal for locations with expansive soils that shrink and swell with moisture changes.
- Uplift Resistance: Certain types of deep foundations can resist uplift forces, such as those caused by high water tables.
- Deep Excavations: Deep foundations allow for extensive below-ground construction projects.
- Confined Workspaces: Caissons create safe and controlled work environments for deep excavations.
Applications of Deep Foundations
- Skyscrapers and High-Rise Buildings: The immense weight of these structures necessitates the deep load-bearing capacity of deep foundations.
- Bridges and Overpasses: Deep foundations ensure stability for bridges, especially those spanning rivers or soft soil.
- Offshore Structures: They provide a secure base for structures built on water, like oil rigs and wind turbines.
- Retaining Walls: Deep foundations support massive retaining walls, holding back soil in excavations.
- Power Plants and Industrial Facilities: They can handle these structures’ heavy loads and potential vibrations.
- Buildings on Slopes: Deep foundations offer stability for structures built on unstable or sloped terrain.
Also read: Types of Foundation in Construction
Final Thoughts
Deep foundations provide a solid foundation for some of our most impressive structures.
They play a pivotal role in ensuring structures can withstand the test of time, particularly in less-than-ideal soil conditions.
Engineers and contractors can make informed decisions by diving deeper into the various types of deep foundations – their applications and advantages.
