Understanding Concrete Foundation Design: Bearing
Designing a foundation is difficult. But once you understand the logic behind how loads travel and how the soil reacts, the entire process becomes intuitive. What Does a Foundation Actually Do? Any foundation acts as a medium between your superstructure (columns, walls, beams) and the soil below it. The structure applies vertical loads, horizontal forces, and moments. The soil resists these loads by providing equal and opposite reactions. These soil reactions govern stability, bearing, sliding, overturning, and structural design of the foundation. How Loads Affect a Footing? When loads act on a footing, it naturally wants to: move downwards (due to gravity loads), slide (due to lateral loads), or overturn (due to moments). But soil has resistance. This resistance creates reaction pressures under the footing. These pressures are what we check during design. In simple words: The structure wants to move. The soil stops it. The result is reactions. Simple Isolated Footing Bearing...