G Gudehus, University of Karlsruhe, & A Weigenbach, University of Dortmund, Germany. This paper was first published in GE’s September 1996 edition.
Eurocode 7 proposes ultimate limit states for the design of structural parts at and in the ground, abbreviated ULS 1B.They have been introduced in order to reconcile the structural Eurocodes, in particular EC2 for concrete, with EC7 within the frame of EC1. The resulting compromise has some shortcomings from a geotechnical point of view:
- The partial factor 1.35 for permanent actions is not tractable in many cases;
- contact pressures among structural parts and ground cannot generally be classified as action or resistance;
- it is difficult to transfer well-established design procedures and global factors.
The German National Application Document (NAD), which appeared April 1996, is an attempt to avoid these shortcomings. The German pre-standard DIN V 1054-100 referred to in this NAD, which is outlined and discussed in the sequel, is intended to:
- incorporate established global factors so that a correction of the said 1.35can also be allowed for;
- better avoid arbitrary interpretations of the partly vague EC7 text;
- avoid over- or underdesign in cases of well-established practice.