In conventional design of deep foundations, some important positive effects evolving from the interaction of the bearing elements and the subsoil (Soil-Structure Interaction) are not utilised. These positive effects especially arise when using Combined Pile-Raft Foundations (CPRFs). The application of numerical methods during the design process of such foundations, which is explicitly allowed in Eurocode 7, is capable of regarding these effects. This paper deals with an approach using numerical methods within the ULS design for complex foundations and discusses case histories where CPRFs are used as a foundation for high-rise buildings in Frankfurt am Main. The paper will be finalised with an introduction to the Seasonal Thermal Storage where the piles of a deep foundation are used as energy piles to store or extract heat in the surrounding subsoil
