Tech Journal

What Is a Shallow Foundation?

A shallow foundation — also called a spread footing or open foundation — is a structural element that distributes the load from a column, wall, or slab to the underlying soil at a relatively shallow depth below the natural ground surface.

The general rule of thumb in geotechnical engineering: if the depth of the foundation (Df) is less than or equal to its width (B), it is classified as shallow. This criterion was first formally articulated by Karl Terzaghi, the father of modern soil mechanics, and remains the foundational benchmark used in practice today.