If you’re planning a large development project, you’ve likely heard of deep foundations and their importance. But what exactly is a deep foundation? In this article, we discuss what deep foundations are, how they work, and why they are so important. We also look at the different deep foundation types available to help you choose the right one for your project. Read on for all the details about deep foundations and how to ensure your next large development project has a strong foundation.
What Is a Deep Foundation?
A deep foundation transfers a structure load to a deeper and more stable layer of soil or rock, typically located at a depth far below ground level and beyond the reach of a shallow foundation. Unlike shallow foundations typically used for smaller structures like houses or small buildings, deep foundations are used for larger and more complex designs, including high-rise buildings, bridges, and dams.
Building piles and drilled shafts can be used to transfer a load of a bridge or other structure to a more stable layer of soil or rock. This keeps the structure secure despite changing water levels or variable soil strengths.
Deep foundations are commonly used for structures in areas with poor soil conditions, like areas with high water tables or soft or loose soil. By transferring the structure’s load to a more stable layer of earth or rock, deep foundations keep the system steady and safe.
Another use for deep foundations is for structures requiring high precision or accuracy, such as nuclear power plants or scientific research facilities. In these cases, deep foundations provide a stable and secure foundation that doesn’t shift or settle over time.
How Do Building Piles Relate to Deep Foundations?
Deep foundations extend below the surface to support heavy loads, or they transfer loads from higher configurations to the deeper layers of soil. Building piles are a type of deep foundation. They’re vertical structural elements driven or drilled into the ground to support the weight of a building or other structures. Building piles are one of the most commonly used types of deep foundation, along with drilled shafts, spread footings, and diaphragm walls. Building piles are essential to many deep foundation systems used in construction projects.
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What Are the Most Common Deep Foundation Types?
Deep foundations are essential in densely populated urban environments because they allow for the construction of large buildings and structures while minimizing disturbance to the surrounding environment. Each foundation type has its own benefits and uses depending on the project’s specific requirements.
These are deep, cylindrical excavations drilled into the ground to support structures like high-rise buildings. They’re preferred in urban areas because they produce less noise and vibration during construction.
Piles are vertical columns driven into the ground to support structures like bridges, skyscrapers, and large buildings. They are advantageous in urban environments because they can be installed in tight spaces and have high load-bearing capacity. Construction with deep foundations relies on various types of pile foundations, including:
- Steel piles
- Concrete piles
- Timber piles
- Composite piles
- Sheet piles
- Boring piles
- Micro piles
- Drilled shaft piles
- Auger-cast piles
- Pipe piles
- Helical piles
These shallow foundations support smaller structures like houses, low-rise buildings, and columns. They are ideal for urban environments because they are easy to construct and can be used in areas with limited space.
These are underground retaining walls used to support extensive excavations or deep basements. They’re great for urban areas because they offer excellent structural stability and allow for excavation in confined spaces.
These are small-diameter piles used to support light structures and repair existing foundations. They are advantageous in urban environments because they carry high loads and can be installed in areas with limited access.
These are piles that are drilled and grouted into the ground using a hollow stem auger. They are helpful in urban areas because they can be installed in limited space and have high load-bearing capacity.
How Do Construction and Deep Foundations Relate?
Construction and deep foundations are two interdependent aspects of the building process that are essential for the stability and longevity of any structure. While construction is focused on the above-ground structure, deep foundations are designed to support the structure’s weight and transfer it to the underlying soil or rock.
Deep foundations are necessary when the soil at the surface can’t bear the weight of the building. The foundation can be either a pile or a drilled shaft inserted deep into the ground to distribute the structure’s load evenly. This ensures the building’s structural integrity by keeping the system level, stable, and secure.
During construction, the foundation is one of the first elements to be installed. Once the foundation is laid, the above-ground structure can be built. The foundation provides support to the building and protects it from natural elements such as earthquakes, floods, and soil erosion.
Several factors need to be considered when designing a deep foundation, including soil composition, groundwater levels, and the load capacity of the foundation. In some cases, a combination of different types of deep foundations may be required to meet the load requirements of the building.
Have a Construction Project Requiring Deep Foundation Solutions? Turn to FNA Engineering.
For over 30 years, FNA has been the engineering firm of choice for developers and contractors in New York City and beyond. Our deep foundation, excavation, geotechnical, and civil and environmental engineering services have played essential roles in some of the most noteworthy construction projects of the past several decades. If you have a building project that needs creative, cost-efficient, and constructible solutions, contact FNA today.
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Over the past 30+ years, FNA has earned its reputation as a premier SOE and Deep Foundation consultant by managing hundreds of projects involving complex, technically challenging sites where highly specialized site conditions, foundations, excavation, and fast-track engineering solutions are required.