Understanding the Different Types of Foundations for the Steel Structure

The foundation is the backbone of the construction structure, which helps to provide necessary support to the entire construction structure and transfers the entire load of the construction structure to the soil. The foundations for the steel structure have been available in different types on the basis of the strength, versatility and durability. For example:

Shallow foundation

The shallow foundation is one of the common types of foundation which has been used in construction structures.

The shallow foundation has been placed close to the surface area of the ground and has been used for those structures which require relatively light loads, and the soil has adequate load-bearing capacity. The shallow foundation can be of different types, including isolated footing, combined footing, strip footing and mat footing.

Deep foundation

The deep foundations have been used in those steel structures, where the soil surface is not strong enough to support the load of the steel structure. In the case of steel structures with heavy loads or with poor soil conditions, the deep foundation has been used. The deep foundation is also categorised into different types, including pile foundation, drilled shaft foundation and pier foundation.

Hybrid foundation

The elements of both shallow foundation and deep foundation have been combined to make a hybrid foundation, which helps to provide additional stability and load-bearing capacity for the construction structure. The pile-raft foundation and the floating foundation are examples of the hybrid foundation.

Concept about steel column footing foundation

The detailed design of the steel column footing foundation involves a reinforced concrete base, which helps to connect the steel column to the ground surface. The steel column footing foundation has been designed to distribute the entire load of the construction structure.

The steel column footing foundation helps to connect the base plate to the footing and also helps to connect the reinforcement bars to provide strength to the construction structure and protect the construction structure from cracking. The design of the steel column footing foundation has been decided by determining the size of the footing and the depth of the footing on the basis of the calculated column loads and the load-bearing capacity of the soil.

Discuss the process of designing the foundation of the construction structure

While designing and constructing the foundation structure, it is important to ensure that the foundation is strong enough to resist the loads throughout the service life of the construction structure. The design of the footing foundation has been done by following several procedures, which are as follows:

The investigation of the soil

Before the beginning of the footing foundation of the structure, the investigation of the soil should be done. This soil investigation procedure helps to identify the important characteristics of the soil beneath, the soil bearing capacity and also helps to know about the different layers of the soil type that has been found beneath. The information obtained from the soil investigation helps the engineers to determine the exact type of foundation that has been applied for the construction's structure.

Structural analysis process

The structural analysis of the construction structure should be performed while designing the footing foundation. To perform the structural analysis process, various software have been used. The structural analysis of the construction structure is necessary to find out the shear forces, bending moment forces and various reactions that act on the structural elements. For example, if G+2 structures need to be constructed, the structural design process needs to be followed for designing each member of the construction structure. In this context, FEA software can be used to perform modelling and structural analysis of the construction structure. Once the structural analysis process has been completed, two types of data are required: one is the reactions from the columns, which will be connected with the footing foundations, and the other is the position or the coordinates of the columns.

The design stage of the foundation structure

After completing the structural analysis process, the foundation needs to be designed on the basis of the requirements of the local standards. This design procedure can be hand calculated or can be done with the help of the foundation design software.

While designing the foundation with the help of the foundation design software, different values have been inserted as input, including the grade of the steel, the grade of the concrete, the type of foundation, and the selection of the structural codes as per the country guidelines.

Optimisation process

The safety factors of the foundation need to be analysed, and the final design of the foundation should be optimised carefully.

To learn more, watch the following video tutorial.

Video Source: Structuraldetails Store

After designing the foundation, engineers are able to experiment with different sizes of the footing foundation, quantity of the foundation and the reinforcement arrangement of the foundation, which helps to make the footing foundation more economical.