The spherical tank is supported only by eleven steel columns that are welded to the shell and connected by a bolted ring that runs all the way around. The stiffeners ensure horizontal stability under wind and earthquake loads. A 3D model was created using RFEM for structural and dynamic calculations, with all components modeled as surface elements. The structure-soil interaction is realized by elastic supports that transfer the stiffnesses of the pile foundations in all directions of the displacements. For more information and references, see Cedeti ingénierie.