A foundation is the lowest part of the building structure which is in direct contact with the ground and transfers its gravity load to the earth. The lowermost section of the foundation which is in direct contact with the sub-soil is called the footing.
|Fig 1. Foundation|
Foundation is generally categorized into two sections viz Shallow foundations and Deep foundations.
|Fig 2. Shallow Foundation and Deep Foundation|
A high rise building must have a strong foundation if it is to stand for a long time. For any structure, its foundation forms the most important part and as it remains inside the ground, it cannot be easily inspected. Hence the failure of the foundation is not noticed until the structure is seriously affected. Therefore extreme care should be taken in the construction and design of foundations to avoid their failure in the future.