Foundation (engineering)
A foundation is the element of a structure which connects it to the ground, and transfers loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics (Geotechnical engineering) in the design of foundation elements of structures.
Shallow foundation
These foundations are common in residential construction that includes a basement, and in many commercial structures.
But for high rise buildings they are not sufficient. A spread footing that changes elevation in a series of vertical steps so that it follows the contours of a sloping site or accommodates changes in soil strata, is called a "stepped footing".