Foundations in construction are generally buried underground, transmitting the carrying loads to the ground. Therefore, building a solid foundation ensures that the structure it supports is stable, the transmitted pressure is less than allowable, and settlement is limited. The foundation must resist the loads and support the structure against horizontal forces such as wind and earthquakes.
Furthermore, the interaction between the soil and the structure depends on the nature of the soil itself and the foundation type supporting that structure. So in this blog, you will learn about the different types of foundation in construction to help you make the best choice for your building project.
Types of Foundation in Construction
Here we will show you the different types of foundations that exist:
Construction with special foundations requires considering two main types of foundations: shallow and deep. Let’s look at each.
- Shallow foundations: Also called direct foundations. In this type of foundation in construction, they rest directly on the resilient soil near the surface. They transmit the load of the structure directly.
- Deep foundations: Also called indirect foundations. These special foundations transmit the load through structural elements, such as piles or caissons, to a deeper, stronger layer of soil.
Let’s know them in detail!
Shallow Foundations: Types, Advantages, and Disadvantages
A shallow foundation transfers the load of the structure to the shallower layers of the ground. The load capacity it can transfer to the ground depends on its size, as it is proportional to its depth. These types of foundation in construction typically have a contact depth of less than 4 metres.
Types
- Footings: isolated, continuous, combined or eccentric (compensated)
- Foundation slabs
- Foundation beams
Advantages
- Lower cost
- Quick and easy construction.
- Reducing environmental impact.
- Minor ground movement.
Disadvantages
- They are prone to ground movements.
- Not suitable for structures with large loads.
- Not applicable on soils with low bearing capacity.
Types of Shallow Foundations
- Isolated or Individual Footing: This simplest foundation type is constructed to support a single column. This is a reinforced concrete block that transmits the load of a pillar to the ground. The most appropriate ground for this type of foundation is usually very firm or solid soil.
- Continuous or Combined Footings: These are similar to single footings, but instead of bearing the weight of a single column, they bear the weight of a wall or a combination of several columns. They are often one of the most widely used solutions, given that they are one of the most economical and easiest systems to implement. They are among the types of foundation in construction suitable for firm or fairly firm foundations.
Also read: 30 Different Types of Columns in Construction
- Concrete Slab Foundation: This type of foundation is the best solution when the soil is very weak or heterogeneous. In this case, the foundation extends across the entire surface of the structure, transmitting its load to a very large portion of the ground. It is also a good solution when the structure has a small surface area relative to its size, as is the case with skyscrapers and towers.
Deep Foundations: Types, Advantages, and Disadvantages
When the surface soil is not strong enough to support the loads of a structure, it is necessary to build a foundation that transmits these loads to deeper, stronger levels. This is also necessary when tensile stresses occur, such as in very tall buildings due to the action of the wind.
These types of foundation in construction generally have a typical depth of between 3 and 6 metres and use either a deeper strip footing or short piles or shallow pile caps. Shallow foundation pits can also be excavated to achieve a higher-strength layer.
Types
- Piles
- Caissons (or “caisson” piles)
- Foundation pits
Advantages
- More load capacity
- High stability on difficult terrain
- Resistance to differential settlements
Disadvantages
- Higher costs
- Longer construction time
- Complexity in construction
- Possible eventualities, such as negative friction
Several Types of Deep Foundations
- Pile Foundation: This is a column-shaped element that transfers the structure’s loads to deeper ground. It can be made of reinforced concrete, steel, or wood and is typically used for large-scale projects due to the large size of the machinery.
- Micropile Foundation: Similar to a pile, but smaller in size. It typically consists of a steel tube placed inside a borehole drilled into the ground and filled both internally and externally with cement grout. It is increasingly used in the construction sector due to its excellent value for money.
- Diaphragm Wall Foundation: These types of foundation in construction act as retaining walls. It is typically used in urban areas when it is necessary to excavate deeply and contain groundwater and soil. For example, it is used during the construction of parking lots, basement tunnels, or roads.
- Caissons Foundation: Caissons are hollow structures, usually made of reinforced concrete, driven into the ground. They are used in situations where excavation is necessary to a considerable depth below the water table or in soft soils. Caissons can be subsequently filled with materials such as sand, gravel, or concrete to provide additional stability.
Comparative Analysis of Different Types of Foundations
Selecting the appropriate type of foundation in construction is a crucial step and depends on multiple factors, such as soil characteristics and structural needs. Below is a comparative analysis of different types of foundation in construction:
How to Choose the Right Type of Foundation in Construction?
The foundation is the backbone of any construction project, and selecting the right type is crucial for the long-term stability and safety of the building. However, one of the biggest challenges for foundation specialists is determining which foundation to choose based on the ground.
Choosing the right types of foundations depends on a prior assessment of the ground, which analyses the bearing capacity, the load-bearing layer, and the water table or underground area. When the soil lacks sufficient resistance, in areas of seismic risk or with a high water table, special deep foundations are used.
Furthermore, it is essential to conduct a structural analysis, assessing the building’s characteristics, including its height and weight, load distribution, and seismic conditions. When the structure is lightweight and the soils are relatively strong, shallow foundations can be used if geotechnical and geological conditions warrant.
For example, it will be possible to determine the most suitable types of foundation in construction when:
– the soil is firm and the structure is light,
– soft soil or low load-bearing capacity with a large structure,
– construction in seismic zones, or
– moderately resistant soils to go for semi-deep foundations.
Additionally, you can contact our team of construction ERP experts to learn how our software can help you manage your foundation and construction projects more efficiently.
Frequently Asked Questions
Q. What exactly is a foundation?
A foundation provides a load-bearing base for a structure. As a solid support, it provides stability and ensures that it doesn’t sink into the ground. You need a foundation, for example, for an occupied house or for certain garden projects.
Q. How many types of foundation in construction are there?
The foundation types differ primarily in their size, the amount of concrete required, and their subsequent load-bearing capacity. If you need a foundation for a landscaping project, you can choose between a shallow foundation, a strip foundation, and a foundation slab.
Q. When do you need a strip foundation?
You use a strip foundation in your garden when a point foundation doesn’t provide sufficient stability. This is often the case with small garden sheds or walls. You can find out whether a strip foundation is suitable for your soil by feeling it. Take a portion of the soil and rub it between your hands. If the soil is crumbly, it is sandy and therefore not stable. If the soil is rather slimy and smooth, it is a stable clay soil.
Q. Which foundations do not require approval?
You can build a foundation in your garden without a permit. However, if you want to erect a structure on it, you may need a permit under certain circumstances, depending on the state. Before you begin construction, contact your local authority. They will provide information about notification and permit requirements.
Q. What is important for deep foundations?
The deep foundation system helps to distribute the weight evenly and reduces the risk of structural failure. As a result, these types of foundation in construction become essential for heavy load-bearing structures such as high-rise buildings, bridges, and large industrial facilities.