Foundation (engineering)
Foundations are designed to have an adequate load capacity depending on the type of subsoil/rock supporting the foundation by a geotechnical engineer, and the footing itself may be designed structurally by a structural engineer. The primary design concerns are settlement and bearing capacity. When considering settlement, total settlement and differential settlement is normally considered. Differential settlement is when one part of a foundation settles more than another part. This can cause problems to the structure which the foundation is supporting. Expansive clay soils can also cause problems.
Glaspaleis
Peter Schunck compared the structure of the building with a ship, floating on uncertain ground. The foundation is basically a concrete trough, that can 'give a little' if any mining shafts were to be dug under it. This 'ship' would then never be able to capsize. During construction, the moat of the old Roman settlement Coriovallum was uncovered, which was the reason to lay the foundation deeper than originally planned. Inside the old walls the subsoil was firm, but outside them it was very bad. Building such a structure on such ground in a mining area was deemed too risky and the ground was cleared until a single layer of equal overall weakness was encountered, a 12 m thick sand layer. This sand is generally considered a bad foundation soil, but in a mining area it is a good choice because it flows and 'gives' evenly in case of a cave-in in a mine below it. Still, Peutz decided that the soil pressure should not exceed 1 kgf/cm² (100 kPa). So for the foundation he used a reinforced concrete slab extending under the whole building. This 50 cm thick beamless foundation slab is mushroom-shaped.