The foundation of a building is constructed in order to transfer the superstructure's load to the ground. An isolated footing is one of the most used types of foundation to support single-columns when they are arranged at a long distance.
An isolated footing must be designed to avoid exceeding its bearing capacity and provide safety against overturning or sliding while preventing the ground from settling. Isolated footing must be applied when the mechanical properties of the ground do not drastically change in the foundation area. It consists the financially most beneficial kind of foundation.
The categories of isolated foundation footings are the following:
1. Pad Footing
A pad or flat isolated footing is constructed by plain or reinforced concrete. Its thickness is constant and its shape can be circular, rectangular or square. It is economic and requires less excavation but its size is highly depended on the load and it is less resistant in lateral forces.
2. Sloped Footing
Sloped isolated footing requires less concrete and reinforcements bars than pad footing. It is constructed cautiously in order to maintain a 45-degree inclination from all sides. The concrete mix used must be stiff in order to avoid sustaining viscous deformation.
3. Stepped Footing
This type of footing includes the construction of a footing step by step until it reaches the desired width. This technique is mostly used in residential buildings but its utilization has been decayed over the last decades.
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