What is a foundation in construction?

The foundation is a part of a structural system to supports and protects a structure's superstructure while also transferring its load-bearing ground. A foundation is a component of a structural system that supports and sustains a building's superstructure while somehow transferring its loads to the ground. It provides and supports a building's superstructure and distributes its loads direct to the ground. The base of the foundations should be below frost level to avoid damages from frequent freeze-thaw periods. It supports and sustains a building's superstructure while somehow transferring its loads to the ground. It also supports and protects a structure's superstructure while also transferring its load-bearing ground.

Types of foundations

The lower component of a structure of the building which distributes vertical and gravity loads to the soil is known as the foundation. Deep foundations and shallow foundations are the two kinds of foundations that are commonly used. A load is transferred to a stratum existent at a shallow depth via a shallow foundation. Weight is transferred to the deeper or lower-level depth below a ground surface by a deep foundation. Any tall building, such as a skyscraper, or one built on particularly poor terrain, needs a deep foundation. If such a structure is intended to expand vertically in the future, then a deep foundation should be considered.

Workers may start constructing the building superstructure once the foundation has already been compacted down securely or dried hard. Spread footings, broad bases (e.g. concrete) which hold walls and piers and disperse the load more than a larger area, are almost always used to support main foundations from low-rise residential structures. To support the external wall, the grade of a concrete beam supported using isolated footings, piers, or piles might be erected on the ground surface, particularly in a structure without a basement. Tall structures also employ spread footings, but at a much larger scale.

Basic classification of foundation in construction

 Trenches are dug deep in the earth until a hard stratum gets reached to build a foundation. Material (concrete) is poured into the trench to create a stronger foundation. The reinforcing cage is inserted into these trenches to improve the foundation's durability. Steel rods projecting outwardly serve as the bones, and they must be linked to the foundation above. The erection of the structure may begin once the foundation was being properly compacted. Concrete, stones, steel, bricks, and other materials can be used to build the foundation. These design loads and the kind of underlying soil influence the material as well as the type of foundation used for the intended building.

 The foundation's design should consider the various consequences of building on the environment. Digging and piling for a deep foundation, for instance, may cause detrimental disruption to the adjacent soil and building foundation. These could occasionally cause difficulties with the neighboring structure's settling. Before having such surgeries, such consequences must be investigated and considered. The waste material generated by the activities must be appropriately disposed of. The foundation must be built to withstand the onslaught of hazardous elements from the outside. 

Basic need to make a foundation construction

The foundation's bottom will be below the frost level to avoid damage from repeated freeze-thaw cycles. Spread footings, which are wide concrete bases that support walls or piers and distribute weight across a larger area, are commonly used to support the foundations of low-rise residential buildings. If a project does not have a basement, a grade concrete beam supported by isolated footings, piers, or piles might be erected near ground level to support the outer wall footing. Spread footings are increasingly being employed in high-rise buildings. Pilings, concrete caisson columns, and constructing directly on the exposed rock are some more options for supporting large loads. A floating foundation made out of stiff, box-like structures put at a depth where the soil weight required to create it equaled the weight of the structure maintained can be used as release soil.

There are three main foundation types; basement, crawlspace, and concrete slab. A fourth, but a less common option, is wood foundations. Structural walls reach beneath basement foundations. Full and daylight are the two most prevalent. A full basement is completely underneath, with really no windows or perhaps a few small ones near the surface. There are two types of basement foundations: completed and unfinished. Heating systems, furnaces, and other home equipment are frequently stored in unfinished basements. Short foundation walls upon footings comprise a crawlspace foundation. Such foundations were typically unheated, although they do contain ventilation to keep moisture out. Those who use poured concrete as well as mortared concrete blocks, but instead users are less expensive than that of a full basement. Because you may store certain goods but not turn them into a living area, many people would consider a half basement to become a crawl space.

In many places, concrete slab foundations, also known as slab-on-grade frameworks, are a popular choice. They work best in regions where the ground does not freeze or thaw all winter. Termite protection is provided by such types of foundation methods. However, since sewerage and sewage pipes are usually hidden behind a few inches in concrete, accessing them can be difficult. Slab-on-grade foundations are among the most cost-effective choices for foundations. As in the north, wood foundations are frequently used. Homeowners might also have a crawl area beneath their house. Basements with stress wood upon the top of concrete floors also are popular, although such a configuration would technically be considered a concrete base. Usually, foundations are classified as shallow or deep. The application of geotechnical engineering, including soil mechanics and rock mechanics, to the design of foundation components of structures is known as foundation engineering.

Basic features of the foundation

For the following reasons, foundations are supplied for all load-bearing structures.:

1. The key cause for any structure's stability is its foundation. The foundation must be solid for the structure to be stable.
2. The right design and construction of foundations provide a proper surface for the substructure to develop in a level and firm bed.
3. A foundation with a unique design aids in preventing lateral movement of the supporting material.
4. A good foundation evenly distributes weight across the bed's surface. This homogeneous transfer aids in preventing the building from settling unevenly. Alteration settlement is an unfavorable result of construction.
5. The foundation's job is to distribute the weight from the structure evenly across a vast base area and subsequently to the earth beneath it. The load that is delivered to the soil should be within the soil's permissible carrying capability.

   A foundation for each structure is designed such that shear failure doesn't occur within underlying soil underneath the foundation structure and allowable load stress is defined as the maximum stress that the soil can endure without failing at the initial service load.

Foundation's role in the construction

The primary roles of the foundation can be enumerated as follows, based on the purposes of the foundation in construction:

• Ensure the structure's overall lateral stability.
• The foundation's purpose is to provide a level platform for the building of the substructure.
• Load distribution is done in an even manner.
• The load intensity is lowered to remain within the soil's safe bearing capacity.
• The influence of soil movement is resisted and avoided.
• The construction of foundations solves the difficulties of scouring and undermining.

Essentials of a food foundation

As in the design and engineering of a good foundation, there's a few basic requirements that must be satisfied. The foundation is planned and constructed to sustain and transmit both dead and imposed loads to the earth. Such transfer should be performed without generating any shifting that could compromise the structural stability of the structure. Differential settlements can be avoided by laying a solid foundation. These issues are exacerbated in areas in which the superimposed loads aren't distributed equally. It is advisable to have a deeper foundation based on the soil and area so that it can withstand any damage or hardship. These are primarily induced by temperature variations, which produce shrinkage and swelling. The foundation must be built in a location that is not affected or influenced by future works or causes.

Context and Application

Foundations are usually shallow or deep. Foundation engineerings is the application of geotechnical engineering, such as soil mechanics and rock mechanics, to the construction of foundation components of structures. Mostly Pressure and stress applications are used to estimate the net forces, resistance and expansion-contraction, and other important parameters for concrete and glass ( with the pre-stressed and tempered condition) and other materials during the construction of the structures such as buildings, bridges, roads, dam, etc. in Civil engineering. 

This topic is useful for the students who are undergoing the following courses:

• Bachelor in Technology 

• Master in Technology

Practice Problems

1. What type of footing is being used for load-bearing masonry structures?

1. Pile
2. Strap
3. Strip
4. Isolated

Ans. Option (c).

Explanation: A strip footing supports the entire weight of a wall. Also, underneath the wall, there's also a continuous footing.

2. Which are the modern types of foundation construction used?

1.  Deep foundation
2.  Shallow foundations
3. Stone foundations:
4.  Both (a, b)

Ans. Option (d).

Explanation: Deep foundation and Shallow foundations

3. Which of the following foundation would be a part of the construction of a building?

1. Above
2. Lower
3. Middle
4. None of the above

Ans. Option (b).

 Explanation: The foundation would be a lower part of the construction of a building.

4. Of which of the following is a soil's shear strength a one-of-a-kind property?

1.  Total stress 
2.  Effective stress 
3.  Both 
4. None

Ans. Option (b)

Explanation:  A soil's shear strength is a one-of-a-kind property that is effective stress.

5. Which form of foundation construction has been most commonly used throughout the construction of buildings?  

1.  Combined Footing
2.  Isolated footing
3. Individual footing
4.  Both b and c

Ans. Option (d).

Explanation: Both of the Isolated footing and Individual footing forms are the foundation construction type that has been most commonly used throughout the construction of buildings.

Related concepts

• Basic Foundation constructions techniques needed
• Features and function of Foundation constructions process
• Different Role of the Type of the Foundation construction techniques based on the applications 
• Its general Applications