Newcastle Chapter

51st Rankine Lecture – Geotechnical Stability Analysis – 2016 Newcastle

Laureate Professor Scott Sloan

About the presentation

Historically, geotechnical stability analysis has been performed by a variety of approximate methods that are based on the notion of limit equilibrium. Although they appeal to engineering intuition, these techniques have a number of major disadvantages, not the least of which is the need to presuppose an appropriate failure mechanism in advance. This feature can lead to inaccurate predictions of the true failure load, especially for cases involving layered materials, complex loading, or three-dimensional deformation.

This lecture will describe recent advances in stability analysis which avoid these shortcomings. Attention will be focused on new methods which combine the limit theorems of classical plasticity with finite elements to give rigorous upper and lower bounds on the failure load. These methods, known as finite element limit analysis, do not require assumptions to be made about the mode of failure, and use only simple strength parameters that are familiar to geotechnical engineers. The bounding properties of the solutions are invaluable in practice, and enable accurate solutions to be obtained through the use of an exact error estimate and automatic adaptive meshing procedures.

The methods are extremely general and can deal with layered soil profiles, anisotropic strength characteristics, fissured soils, discontinuities, complicated boundary conditions, and complex loading in both two and three dimensions. Following a brief outline of the new techniques, stability solutions for a number of practical problems will be given including foundations, anchors, slopes, excavations, and tunnels.

About Professor Scott Sloansloan_s

Scott Sloan is Laureate Professor and Director of the 220-strong Australian Research Council (ARC) Centre of Excellence for Geotechnical Science and Engineering at the University of Newcastle, NSW, Australia.  He is an elected Fellow of the Australian Academy of Science, the Australian Academy of Technological Sciences and Engineering, the Royal Academy of Engineering, and the Royal Society of London.  In 2005 he received the Monash University Alumnus of the Year Award in Civil Engineering, while in 2015 he was named as NSW Scientist of the year and also cited by Engineers Australia as one of Australia’s Top 100 Most Influential Engineers. Scott is the recipient of various accolades including the 2000 Telford Medal and 2007 Telford Premium from the ICE (for the best paper published in any of the Institution’s journals and the best paper on applied mechanics, respectively), an invitation to give the 2003 E H Davis Lecture from the Australian Geomechanics Society (for outstanding contributions to theoretical geomechanics), a Centenary Medal in 2003 from the Prime Minister of Australia (for service to Australian Society in Civil and Geotechnical Engineering), the 2005 Desai Medal and 2008 Booker Medal from the International Association for Computer Methods and Advances in Geomechanics (for outstanding contributions to computational geomechanics), the 2005 Thomas A Middlebrooks Award from the American Society of Civil Engineers (for a paper of special merit in the field of geotechnical engineering), and a 2010 Fellows Award from the International Association of Computational Mechanics.

Scott is a co-editor of the leading international journal Computers and Geotechnics and a member of the editorial board for five other international journals.  He has held visiting professorships at MIT and UPC (Barcelona), and is a board member for the International Association for Computational Methods and Advances in Geomechanics (IACMAG). He chaired the Engineering, Mathematics and Informatics College of Experts for the Australian Research Council in 2010, as well as Sectional Committee 5 for the Australian Academy of Science (which recommends the election of new fellows in the Applied Physical and Engineering Sciences) for the period 2011-2012.  Scott currently serves on the Council of the Australian Academy of Science and is one of the world’s most highly-cited geotechnical researchers with a Scopus H-index of 42 and 16 papers with >100 citations (three of which have > 200 citations). His research interests include computational stability analysis, nonlinear finite element algorithms, geotechnical modelling, soft soils, modelling unsaturated soil behaviour, nonlinear optimization methods, and georemediation.

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