Foundations mainly classified as two
Selecting the suitable foundation for our building plays a vital role in the betterment of our building project. Lets discuss the types of foundations for our buildings.
- Shallow Foundations
- Deep Foundations
![](https://kmhp.in/wp-content/uploads/2022/09/weetw.jpg)
Shallow Foundation
Shallow foundation has some sub classifications
a. Individual footing or isolated footing
b. Combined footing
c. Strip foundation
d. Raft or mat foundation
a. Individual footing or an isolated footing
Individual footing or an isolated footing is the most common type of foundation used for building constructions. This foundation is constructed for a single column ,so it is also called as pad foundation. The shape and size of individual footing is also very important .
![](https://kmhp.in/wp-content/uploads/2022/09/Individual-footing.jpg)
The shape of individual footing is square or rectangle based on the loads carried by the columns. The size is calculated based on the load on the column and the safe bearing capacity of soil.
b. Combined footing
![](https://kmhp.in/wp-content/uploads/2022/09/combined-column-footing.jpg)
Combined footing is actually the combination of isolated footings but their structure differs. These footing is constructed when two or more columns are adjacent and their isolated footings overlap each other. The shape of this footing is a rectangle and is used when loads from the structure is carried by the columns. https://kmhp.in/ditch-cement-use-jaggery-eggs-to-build-homes-tn-engineer-shows-you-how/
c. Strip foundation
Strip or wall footings is also known as spread footing ,this type of foundations are those whose base is wider than a typical load-bearing wall foundations.
![](https://kmhp.in/wp-content/uploads/2022/09/q-edited.jpg)
The wider base of this footing type spreads the weight from the building structure over more area and provides better stability. Spread footings and wall footings are used for individual columns, walls and bridge piers where the bearing soil layer is within 3m from the ground surface.
d. Raft or (mat foundation)
Raft or mat foundations are spread across the entire area of the building to support heavy structural loads from columns and walls. These type of foundations are used when the loads from the structure on columns and walls are very high.
![](https://kmhp.in/wp-content/uploads/2022/09/raft-or-mat-foundation.jpg)
This is used to prevent differential settlement of individual footings, thus designed as a combined footing of all the load-bearing elements of the structure.
Deep Foundations
These type of foundations again classified as pile foundation and Drilled Shafts or caissons
a. Pile foundation
![](https://kmhp.in/wp-content/uploads/2022/09/pile-1-edited.jpg)
Pile foundation is a type of deep foundation which is used to transfer heavy loads from the structure to a hard rock layers much deep below the ground level, where shallow foundations such as spread footings and mat footings cannot be used. These are generally used for soils where soil conditions near the ground surface is not suitable for heavy loads. The depth of hard rock layer may be 5m to 50m deep from the ground surface.
b. Drilled Shafts or (caissons)
Drilled shafts or caissons, is a type of deep foundation which has an action similar to pile foundations but having a higher load transfering capacity. It resists loads from structure through shaft resistance, toe resistance and/or combination of both of these. It is used where the depth of hard rock layer below ground level is located within 10m to 100m .
![](https://kmhp.in/wp-content/uploads/2022/09/drilled-shaft-edited.jpg)
- Editor : Jubin Raju Mathew