The Safety Concept in German Geotechnical Design Codes

The Eurocodes were officially adopted in Germany on 1st July 2012. Since then, application of the partial safety concept has been mandatory in all areas of structural engineering. The partial safety concept creates the impression that partial factors based on probability theory are applied to actions or effects of actions and resistances depending on the degree of uncertainty in each case. This is hardly possible in geotechnical engineering. European geotechnical engineers have therefore decided that the partial factors for the permanent and variable actions from the ground should be the same as those used in other areas of structural engineering for the sake of consistency in the field of construction. In Germany, the partial factors for the resistances from the ground have been selected so that the safety level is more or less the same as the tried-and-tested global safety level. In other words, the application of the partial safety concept results in approximately the same dimensions for foundations and geotechnical structures as those obtained with the global safety concept in the past. Thus, on closer inspection, the partial safety concept in its present form is, in geotechnical engineering at least, a modified global safety concept. Users are faced with the challenge of having to apply a concept which in some respects is new and more complex. However, this is reasonable when one considers the important contribution that has been made to placing European construction standards on an urgently needed common basis, thus promoting the unification of Europe.