Need and Function of Foundation
A foundation can be defined as that part of a structure which serves to transmit the forces and moments coming from the structure above the ground to the supporting soil ensuring stability against shear failure and also ensuring that excessive deformations beyond permissible total and differential settlements do not take place. Generally, in the case of buildings, the walls or column are provided with enlarged bases which rest on the soil at a shallow depth. Bridge foundations on the other hand are much deeper and larger to take into account the higher loads and scour considerations. Earth embankments do not require structure, however, have a special foundation structure. These examples clearly show that a foundation structure is needed when there is material difference at the bottom of superstructure such as steel, concrete etc., and the ground which supports il. The smaller sections of columns and piers are sufficient for transmitting loads. The soil being weaker will require a much larger area on which the superimposed load has to be spread