Slope Stability Analysis: From Taylor’s Charts to Finite Elements

Professor D.V. 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 1930’s 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

Professor D.V. Griffiths Colorado School of Mines

Vaughan Griffiths is a Professor of Civil Engineering at the Colorado School of Mines. His interests lie in the application of finite element and risk assessment methodologies in civil engineering. His papers on slope stability are among the most highly cited in the geotechnical engineering research literature. He is the co-author of three textbooks that have gone into multiple editions including the Chinese language on “Programming the Finite Element Method” by Smith and Griffiths, “Risk Assessment in Geotechnical Engineering” by Fenton and Griffiths and “Numerical Methods for Engineers” by Griffiths and Smith. He gives regular short-courses on Risk Assessment in Geotechnical Engineering for practitioners (often with Gordon Fenton), with recent offerings in China, New Zealand, Australia, Colombia, Norway, Canada, Taiwan and the USA. Professor Griffiths is an editor of Computers and Geotechnics and was on the Advisory Panel of Géotechnique from 2012-2018. In 2017, he was named the Cross-Canada Lecturer by the Canadian Geotechnical Society and received the H. Bolton Seed Medal from the ASCE/Geo-Institute. He served as an ASCE Director from 2010-2013.

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