Nachweisverfahren des EC 7-1 für geotechnische Bemessungen in Deutschland

When Eurocode 7: Geotechnical Design, Part 1: General Rules (EC 7-1) is implemented in the European Member States, each state will need to make two important decisions concerning the design of geotechnical structures. Three design approaches are described in the code and each state can select the one that best suits its national design traditions and stipulate its use in geotechnical design. Furthermore, the Member States must establish the values of the partial factors in accordance with national safety requirements. Both, the choice of design approach and the selection of the partial factors, must be seen as a single unit as they are interdependent. The selection of the design approach and the numerical values of the partial factors in Germany was based on the principle that the safety level of the global safety concept that has been used successfully for decades should be maintained as far as possible, i.e. a geotechnical design in accordance with EC 7-1 should result in more or less the same dimensions as the former global safety concept. A comparative design, in which each of the three Design Approaches in EC 7-1 is applied to a strip footing, is used to illustrate the option that has been selected for Germany. It shows that the Design Approach DA 2*, in which the partial factors are applied at the end of the calculation when the limit state equation is checked, not only best fits the tried and tested safety level of the former global safety concept but also results in the most economic design.