Inevitably, soils deform under a load of foundation structures. The total vertical displacement that occurs at the foundation level is termed as settlement. 

The cause of foundation settlement is the reduction of volume air void ratio in the soil. Moreover, the magnitude of foundation settlement is controlled by many factors type as soil and foundation structure. 
Foundations on bedrock settle a negligible amount. On the contrary, Foundations in other types of soil such as clay may settle much more. 
An example of this is Mexico City palace of fine arts has settled more than 15 feet (4.5m) into the clay soil on which it is founded since it was constructed in the early 1930s.
However, building foundation settlement is normally limited to amounts measured in millimeters or fractions of an inch. 
Structures will suffer damages due to settlement of its foundation specifically when the settlement occurs in a quick manner. In this article, different types of foundation settlements along with their cases and expected effects on the structure will be discussed.