How many types of foundation are there based on depth?

Let me tell you first that any building structure's major supporting element is its foundation. The building's lowest point is in direct touch with the ground. It securely distributes all structural weight to the ground. Let’s dig in deep to know about the different types of foundation.

Foundation and its types:

For the construction of structures like residences, buildings, etc., there are typically two primary types of foundation (i.e. shallow & deep foundation). While you select a foundation for building construction, it is necessary to consider its compatibility. Since the qualifying criteria for a foundation depend on the soil and weight of the project. This will guide you on how many types of foundation are there based on depth.

A) Shallow Foundation

In a shallow foundation, the breadth and depth of the foundation are similar. Such foundations are built in soil layers that can support the weight of the structure at greater depths (up to 1.5 m). Generally, the depth is smaller than the width.

1) Wall or Strip Footing: Wall foundations are constant in their distribution along the wall's direction and assist in transferring the wall's weight to the ground. This footing is appropriate for use in thick sand and gravel where the weights to be handled are light and affordable. The breadth of this kind of foundation is two to three times that of the wall on the floor level.

2) Isolated footing: It is best for depths more than 1.5 metres. This footing consists of flat slabs and can be built out of unreinforced or reinforced concrete. The foundation of the column is broad in these foundation types.

3) Combined Footing: The combined footing is a sort of foundation that is built larger using two or more columns in a row. When a column's footing capacity can go beyond the line, it is used. It is also appropriate when the two columns are placed near together and the foundation's soil has a low bearing capability.

4) Cantilever or Strap Footing: A strap beam termed a cantilever footing is used to join other internal footings when an outer footing is unable to extend outside the site boundary. Cantilever footing is another name for strap footing.

5) Mat or Raft Foundation: It is also known as the fleet foundation. a mat foundation is a connected slot that completely encloses the space underneath a building and supports all of the columns and beams.

B) Deep Foundation

A deep foundation is one that is built considerably below the ground's surface and has a depth that is more than its width. It is usually 3 metres below the surface.

1) Pile foundation: A pile foundation uses a curved element with a tiny cross-sectional area compared to its length to move loads either by friction or bearing. This sort of floating foundation relies on friction between the skin to provide support for the footing.

2) Pier Foundation: The pier foundation is a cylindrical part of the structure that is buried underground. It bears high loads that are too great for shallow foundations. This foundation, as opposed to a pile foundation, could only transfer loads through bearing.

3) Caissons Foundation: It is also known as boxes or cases. Caissons are hollow blocks that are typically built on-site and are filled with heavy-duty components. They are often only used for large foundation work due to their high construction costs.

These are the different types of foundation you are now aware of.