EN 1997-1 introduces three design approaches into the analysis; they differ by the application of partial factors.
According to EN 1997-1 the partial factors are generally applied to load actions, their impact on properties of foundation soil M, resistance R or both. The values of partial factors not only differ by the assumed design approach, but also by the type of the analyzed geotechnical task (support structures, piles, etc.). The values of partial factors are in general specified by the Eurocode in Annexes A; the national choice of values of partial factors specifies NA. The program automatically displays the required coefficients depending on the selected design approach or on the selection of other parameters in the setting.
Regarding the fact that individual Design approaches introduce the partial factors into the analysis in a different way (e.g., partial factors on actions on a structure and the resulting structure resistance or actions and soil parameters) it is logical that the results attributed to these design approaches may also considerably differ. If the National Annex does not recommend a Design approach for a given geotechnical task, it is up to the designer to select it (and therefore also to evaluate whether the results correspond to the analyzed situation).
- Design approach 1 - Verification is performed for two sets of coefficients (Combination 1 and Combination 2) used in two separate analyses. Coefficients are applied to load actions and to material parameters.
- Design approach 2 - Applies partial factors to load actions and material resistance (bearing capacity).
- Design approach 3 - Applies partial factors to load actions and at the same time to material (material parameters of soil).
"New settings" dialog window, analysis based on EN1997 - Selection of design approach