Slope stability analysis by means of finite element limit analysis and finite element strength reduction techniques. Part II: Back analyses of a case history. (October 2015)

• Record Type: Journal Article
• Authors: Tschuchnigg, F.; Schweiger, H.F.; Sloan, S.W.
• Is Part Of: Computers and geotechnics. Volume 70(2015)
• Page Start: 178
• Page End: 189
• Publication Date: 2015-10
• Subjects: Finite element limit analysis -- Finite element method -- Strength reduction technique -- Slope stability -- Non-associated plasticity -- Back analysis; Engineering geology -- Data processing -- Periodicals; Soil mechanics -- Data processing -- Periodicals; Rock mechanics -- Data processing -- Periodicals; 624.1510285
• DOI: 10.1016/j.compgeo.2015.07.019
• Languages: English
• ISSNs: 0266-352X

Abstract

Abstract: This paper deals with a back analysis of a slope failure. The case history investigated is located in an alpine environment in central Europe and is characterized by a very steep original terrain, indicating in situ soil with high strength. To study the factor of safety, two different approaches applying the so-called φ ′/ c ′ reduction are used, namely finite element limit analysis and strength reduction finite element analysis. Comparison of a strength reduction technique with rigorous finite element limit analysis confirms that the factors of safety (FoS) obtained are very similar for associated plasticity, an intrinsic assumption of limit analysis. For non-associated plasticity, a modified version of the so-called Davis approach has been applied because it has been shown that the original formulation proposed by Davis works well when the FoS is defined in terms of loads but is not appropriate when the FoS is defined in terms of soil strength. The results show that, with the modified Davis parameter, both strength reduction finite element analyses and finite element limit analyses provide very similar factors of safety. The key advantage of limit analysis, however, is that the value of the FoS can be bracketed from above and below with upper and lower bound calculations.