Maximum forces on soil

This calculation rule determines the maximum possible load on a foundation strip or plate in relation to the collapse of the subsoil.

Method used:

Although it is not possible to ascertain whether calculations of limiting situations on the basis of the assumptions of the plasticity theory for materials with internal friction, such as sand over or under estimate the actual failure load, they are still very often used. An example of such a calculation is that for the bearing capacity (also often termed the equilibrium bearing capacity) of a strip foundation on sand. Prandtl made a calculation for this based on the assumption that in an area on the surface the equilibrium equation and the Mohr-Coulomb criterion are always satisfied. The material in the entire area will thus have the same collapse moment (see figure below).