The substructure which is the lowest part of the building which rests on soil and transfers the load of the superstructure to the ground is called foundation.
The purpose of the foundation is to uniformly transfer the load of the building to a larger subsoil area. This reduces the intensity of load by expanding the area of distribution. Foundation sustains the load of the building without yielding. It also provides a levelled surface for construction work above like concreting and masonry work. Foundation provides stability and strength to the building against various forces such as wind, rain. It holds the building for safety against sliding, overturning & bending moment due to these forces. Hence foundation is the most important component of the building on which building stands.