Characteristic values of geotechnical parameters in Eurocode 7. Issue 4 (21st January 2019)

• Record Type: Journal Article
• Authors: Prästings, Anders; Spross, Johan; Larsson, Stefan
• Is Part Of: Proceedings of ICE. Volume 172:Issue 4(2019:Aug.)
• Page Start: 301
• Page End: 311
• Publication Date: 2019-01-21
• Subjects: codes of practice & standards -- geotechnical engineering -- risk & probability analysis; Geotechnical engineering -- Periodicals; 624.151
• DOI: 10.1680/jgeen.18.00057
• Languages: English
• ISSNs: 1353-2618

Abstract

Abstract : Lack of harmonisation between reliability-based design and the partial factor method in Eurocode 7 (EN 1997-1:2004) is preventing the widespread introduction of a risk-based concept in geotechnical design. This paper discusses how uncertainties are managed according to EN 1997-1:2004 and possible implications of not harmonising the current safety format with reliability-based design. One of several challenges highlighted is how EN 1997-1:2004 defines the characteristic value and design value. The characteristic value is therein defined based on a classical frequentist approach through a confidence interval. From a Bayesian point of view, the current definition does not treat the characteristic value as an uncertain variable. Consequently, the definitions of the characteristic value and design value in EN 1997-1:2004 feature weak connections between uncertainties in the geotechnical properties and the consequences of failure, as regulated by the target reliability index.