• Exploring Different Types of Construction Foundations

    May 25, 2024 | By Kenza TMT Steel Bars

    Whenever we think of constructing any building, be it a house, office, or any other structure, the first thing we usually think about is how it will look and what materials we will use to make it. But one of the most important things that we need to think about before all that is something that you don’t see- the foundation. It is the lowest part of a building, and its main purpose is to distribute the weight of your building evenly to ensure safety and stability.  There are different types of foundations used for different purposes.

    Construction Process of Foundations

    Before you start laying the foundation, you need to inspect the site to understand what lies beneath the surface of the soil, what type of soil it is, whether there is any groundwater available in the area, its levels, and/or any other potential issues that could affect the stability of the building.   Based on the findings, your engineer will design a foundation that is best for the expected load and other conditions. This will help them select the type of foundation and plan the layout. 

    Workers will excavate the soil to the required depth. They will then lay reinforcements to strengthen the foundation. The best TMT Steel bars are usually used for this purpose. Then they pour the concrete around the bars and leave it to cure where the concrete will harden and gain strength. Your foundation is now ready.

     

    Types of Foundations in Construction

    The foundation of your building can be shallow or deep. What type of foundation you need to use depends on the type of soil you are constructing, the load of the building, and its design. 

    Shallow Foundations

    If the soil close to the surface is strong enough to support the load of your building, then your engineers will opt for shallow foundations. They usually have a depth of less than 3 meters and are more economical than and easier to construct if you compare them to deep foundations. Some common types of shallow foundations are

    Isolated Spread or Individual Footing

    In these types of foundations, each column of your structure will have its isolated footing which directly transfers the load to the soil underneath. In some cases, there will be concrete padding over which the load is spread to reduce the pressure of your structure on the soil

    These are often commonly used because they are economical and are suitable for buildings up to five storeys high. The design and construction of these foundations are simple and they use very little materials. However, you cannot use these foundations where the soil is weak or in areas with frequent seismic activity.

    Wall Footings or Strip Footing

    These foundations are longer and narrower than individual footings. They are usually used if your building has narrow column spacing. If you are using wall footings, your construction will be simple and economical, especially if the wall loads are extensive. But it might require additional reinforcements if the soil on which you are building is not strong.

    Combined Footings

    If the columns of your structure are closer together than individual footings become impractical, you can use combined footings. They can create a continuous support system to spread the load evenly. They are also highly recommended if the columns are irregularly placed. However, these are a bit more complex to design and construct and will not work if you do not have precise load calculations

    Cantilever or Strap Footings

    These types of footings are used if your structure is close to another building or unrelated footing. They are the best option to use in sites with space constraints and can avoid interference from nearby elements. You need to be very careful about the alignment and reinforcements of strap footings are the designs are complex to construct.

    Raft or Mat Foundations

    Unlike the footings mentioned till now, mat foundations look like a mat, which essentially makes it a large slab that covers the entire area of your structure. It is designed to support all the columns and walls giving it a solid and continuous base. They are ideal for weak soils. However since they require a lot of concrete and steel, mat foundations are quite expensive. 

    Deep Foundations

    If the soil in the site of your structure is not strong enough to support the structure you are planning to build, your engineers will have to make use of deep foundations, where the base soil layer is more solid. Here, the foundations are deeper than three meters. Some of the main types of deep foundations are.

    Pile Foundations

    In these types of foundations, engineers use materials like steel, concrete, or timber are to make long, slender columns that reach stronger soils. On one hand, you can use them to support very heavy loads and are effective in areas that have high water tables. But on the other hand, you require specialized equipment and materials to make them, which makes them quite costly. If you instill pile foundations, they can cause vibrations and become quite noisy.

    Pier Foundations

    They are similar to pile foundations where you dig large cylindrical columns into the ground and fill them with concrete. They are not as expensive as pile foundations and do not disturb the soil as much. But it does take more time and labor and requires you to constantly monitor the process to ensure that it is precise.

    Caisson Foundations

    These are foundations usually suitable if your structure requires deep-water construction. In this case, you sink watertight structures into the ground and then fill them with concrete. They are very strong and can handle heavy loads but are quite expensive to construct.

     

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