The static equilibrium limit state design involves checking whether the foundation remains stable in its location under the applied actions and whether failure due to overturning occurs.
According to EN 1997-1 [1] 2.4.7.2, the design is performed by comparing the stabilizing and destabilizing moments at the edges of the foundation.
EN 1997-1: Static Equilibrium
Determination of Actions
For the design, the destabilizing moments at the foundation edges are determined. These result primarily from horizontal forces as well as from vertically applied loads with eccentricity.
Determination of Resistances
The destabilizing moments are counterbalanced by stabilizing moments, which result primarily from the vertical loads as well as the self-weight of the foundation and the overlying soil.
Design
The design is performed separately for each governing foundation edge. The ratio of destabilizing to stabilizing moments is determined:
The governing value is the maximum of all directions considered.