Computational Slope Stability Analysis

Prof. Vaughan Griffiths

Slope stability analysis remains a central activity for geotechnical practitioners and a continued area of interest and research for academics. A wide range of methodologies for slope stability analysis have been developed, ranging from Taylor’s charts from the 1930s to state-of-art random finite element methods for probabilistic analysis. The lecture describes two simple slope stability analyses that can lead to unconservative (unsafe) solutions. Firstly, a classical problem solved by Taylor is revisited using (i) simple optimization, (ii) elastic-plastic finite elements with strength reduction and (iii) upper- and lower-bound finite element limit analysis. The results show the benefits of the finite element approaches, especially as the slope becomes relatively flat where the simple approach starts to overestimate the factor of safety. Secondly, a probabilistic slope stability analysis is performed using (i) a simple analytical approach and (ii) the random finite element method (RFEM). For the case considered, the analytical approach is shown to underestimate the probability of failure, by failing to account for spatial variability in the form of a correlation length.

About the speaker

Prof. Vaughan Griffiths Professor of Civil Engineering, Colorado School of Mines-USA, Fulbright Distinguished Chair, University of Newcastle-NSW

D. Vaughan Griffiths PhD, DSc, PE, D.GE, C.Eng, FICE, Dist.M.ASCE is a Professor of Civil Engineering at the Colorado School of Mines, USA, and a Fulbright Distinguished Chair at the University of Newcastle, NSW. His research interests lie in application of finite element and risk assessment methodologies in geotechnical engineering, and his papers on slope stability analysis are among the most highly cited in the geotechnical engineering literature. He is the co-author of three textbooks that have gone into multiple and foreign language editions on “Programming the Finite Element Method”, “Risk Assessment in Geotechnical Engineering” and “Numerical Methods for Engineers”. He gives regular short-courses on Risk Assessment for practitioners, with recent offerings in Australia, Canada, China, Colombia, New Zealand, Norway, Taiwan, and the USA. Professor Griffiths is a past-editor of the journals Computers and Geotechnics, Journal of Geotechnical and Geoenvironmental Engineering and Géotechnique. In 2017, he was named the Cross-Canada Lecturer by the Canadian Geotechnical Society, and the same year received the H. Bolton Seed Medal from the ASCE/Geo-Institute. He served on the Board of Direction of ASCE from 2010-2013 as the Region 7 Director, and was inducted as a Distinguished Member of the ASCE in 2020. He gave the TH Wu Distinguished Lecture in 2021 and the Wilson Tang lecture in 2022.

The event is organised by the QUT (Queensland University of Technology) School of Civil and Environmental Engineering and supported by the Queensland Chapter of the Australian Geomechanics Society.

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