The design of highly unfavorable core loading according to DIN EN 1997-1[1] A 6.6.5 checks if a gaping joint occurs beyond the centroid of the foundation base due to permanent actions and the most unfavorable load combination.
Permanent Actions
The resulting characteristic loading Vk in the foundation base should lie within the first core area. Only actions are considered, resistances are not.
The verification that Vk is within the first kernel area is as follows:
Most unfavorable combination of permanent and variable actions
The resulting characteristic stress Vk should not lie outside the second kernel area. Also in this case, only actions are considered.
The verification that Vk is located outside the second kernel area is as follows: