For all types of construction works the aspects safety, serviceability and sustainability have to be focused during the planning phase, the design phase, the construction phase and in the service phase. Particularly this has to be considered for complex deep foundation systems like the Combined Pile-Raft Foundation (CPRF). The basis for a successful realisation of a project is an adequate soil investigation and a high-level design. For risk mitigation an independent peer review and special technical solutions are necessary. In geotechnical engineering Eurocode 7 (EC 7) defines the scope of necessary measures in relation to the complexity of the project. The complexity of the project is described by the Geotechnical Category GC 1 to GC 3. For the Geotechnical Category GC 3, this is the category for projects with a very high complexity, for risk mitigation comprehensive measures are necessary. The paper explains risk management and risk communication by several examples of realized CPRFs. All examples belong to the Geotechnical Category GC 3.