Implications of variationally derived 3D failure mechanism. (6th June 2016)

• Record Type: Journal Article
• Authors: Zhang, Fei; Leshchinsky, Dov; Baker, Rafi; Gao, Yufeng; Leshchinsky, Ben
• Is Part Of: International journal for numerical and analytical methods in geomechanics. Volume 40:Number 18(2016)
• Page Start: 2514
• Page End: 2531
• Publication Date: 2016-06-06
• Subjects: slope stability -- 3D stability analysis -- variational analysis -- limit analysis -- limit equilibrium -- kinematic admissibility; Soil mechanics -- Mathematics -- Periodicals; Rock mechanics -- Mathematics -- Periodicals; 624.1510151
• DOI: 10.1002/nag.2543
• Languages: English
• ISSNs: 0363-9061

Abstract

Summary: This paper revisits the variational limit equilibrium (LE) analysis of three‐dimensional (3D) slope stability in the context of limit analysis (LA). It proves the kinematic admissibility of the 3D mechanism in LA, although it was derived from LE variational extremization. It also includes algorithms in the realm of LA that are associated with the variational mechanism. A comparison between the variational results and reported LA upper‐bound or LE closed‐form results is conducted. It demonstrates that the variationally derived mechanism consistently yields upper‐bound solutions for 3D symmetrical slopes that are as accurate as those produced by postulated mechanisms in LA. However, the results are more critical than those derived from spherical failure mechanism in LE. The generalized log spiral 3D mechanism rigorously legitimizes the variational slope stability analysis in both frameworks of mechanics LE and LA. Stability charts were produced where the 3D factor of safety can be assessed for a constrained length of failure, while including factors like pore water pressure and seismic loading. The results presented within this study demonstrate the capabilities of the variational 3D solution and can be used to evaluate approximate methods, numerical or closed‐form, developed in 3D slope stability analyses. Copyright © 2016 John Wiley & Sons, Ltd.