Presented by Prof Helmut F. Schweiger
Over the last decades numerical methods have gained increasing importance in practical geotechnical engineering and have become a standard tool in geotechnical design, widely accepted by the geotechnical profession. However, there is still a significant gap between research (what can be done) and practice (what is done) and in many cases unnecessary simplifications are made in practice preventing exploitation of the full power of numerical analyses. One reason for this discrepancy is a lack of transfer of knowledge from research into practice but also a lack of theoretical background of numerical methods, constitutive modelling and modern soil mechanics. In this paper, after a short note on constitutive models, the application of advanced numerical models for solving practical geotechnical problems is shown whereas the examples have been chosen in such a way that different aspects are highlighted in each case. These examples should demonstrate that with little extra effort much more can be gained in understanding of a particular problem compared to an analysis introducing too many simplifications. Results from fibre-optic measurements for a pull-out test of a ground anchor in soft soil could be reproduced by employing advanced constitutive models, in particular for the grout, in the bonded length of the anchor. For this test a class-A prediction has been made and numerical results have then been compared with in-situ measurements. The back-analysis of a slow-moving landslide is presented next, where the rate of deformation is influenced by water level changes in a reservoir for a pumping power plant, creep of lacustrine sediments and environmental effects such as rainfall infiltration. Results from a back-analysis of a slope failure highlight the advantages of numerical methods over conventional limit equilibrium calculations. Finally some results of modelling cone penetration testing in structured soils are presented. It is shown that the increase of undrained shear strength due to vacuum consolidation can be quantified by comparing numerically obtained cone resistances before and after vacuum consolidation.
After obtaining his Ph.D. from the University of Wales, Swansea, UK Prof. Helmut F. Schweiger joined the Institute for Soil Mechanics, Foundation Engineering and Computational Geotechnics at the Graz University of Technology where he was initiating and leading the Computational Geotechnics Group for 25 years.
Although now “formally” retired from University, he is still active in research and international committees. His main research interests are the development of multilaminate models for soils and the assessment of the influence of the constitutive model for solving practical problems, in particular deep excavations, deep foundations and tunnels. His research is reflected in more than 350 publications in International Journals and Conference Proceedings and invitations to keynote and plenary lectures at International Conferences on Soil Mechanics and Computational Geotechnics. He serves on a number of editorial boards of international journals, including Geotechnique (2004-2007, 2018-2020), Computers and Geotechnics and is Associate Editor of the International Journal of Geomechanics.
In 2005 he received the “Excellent Contributions Award Regional” of the International Association for Computer Methods and Advances in Geomechanics, the “Best Paper Award” of the Japanese Geotechnical Society and in 2010 the “George Stephenson Medal” of the Institution of Civil Engineers, London, UK for a paper published in Geotechnique. He delivered the Szechy Lecture and the Suklje Lecture in 2018. Helmut is the current president of the Austrian Geotechnical Society and the Chairman of the upcoming 21 International Conference on Soil Mechanics and Geotechnical Engineering to be held in Vienna in June 2026.
Presented by Prof. SW Jacobsz
Details to follow.
SW Jacobsz completed a BEng (1994) and MEng (1996) degrees at the University of Pretoria and a PhD at the University of Cambridge in 2002. He worked for Jones & Wagener as a geotechnical engineer for a total of 10 years and was appointed Associate Professor in the Department of Civil Engineering at the University of Pretoria in 2010. His research interest includes physical modelling of geotechnical and soil-structure interaction problems and topics related to unsaturated soil mechanics such as sinkholes, tailings and expansive clays. He has been involved in several large-scale field trials including large surcharge trials on residual dolomite, large-scale testing of piles in expansive clays and monitoring the in-situ state on a range of tailings dams. A received the South African Geotechnical Medal from SAICE for this contribution of Geotechnical Engineering in South Africa in 2023.
Presented by Mr Trevor Green
Characterising dolomitic conditions for sites has become better understood and more standardised since the publication and widespread use of SANS 1936. This may, however, provide a false level of confidence, as there remains significant uncertainty in respect to the actual dolomite conditions underlying a site. Unexpectedly variable or poor conditions can have a profound influence on the appropriateness of the design solution, and the successful construction of either foundations or remedial measures.
Some recent high-profile projects have allowed an unusually detailed level of investigation for sites underlain by dolomite. This includes a mall development in Midrand and the remediation of several sinkholes along the R21.
This presentation describes these interesting case studies, where the results of very comprehensive investigations could be compared to the actual geotechnical conditions encountered. Thus, providing a unique insight into the variance of dolomitic conditions, and some of our assumptions in terms of characterising sites during standard dolomite investigations.
Trevor Green graduated with a BSc (Eng) in 2002 from the University of Witwatersrand. He started his career at Grinaker-LTA and joined ARQ Consulting the following year. While at ARQ, Trevor was privileged to have the opportunity to design foundations for several of the stadiums used for the Soccer World Cup and work extensively on the Gautrain Rapid Rail Link.
In 2007, Trevor left ARQ to start Verdi Consulting Engineers (Verdicon). Verdicon quickly established itself as one of SA’s leading geotechnical consulting engineering firms. In 2017, Jones & Wagener (J&W) purchased Verdicon and appointed Trevor as Head of the Geotechnical Department, and later as a Director of J&W, as well as a Director of J&W International, UK, Ghana and Namibia. Trevor left J&W in 2025 and currently operates as an independent geotechnical engineer.
Trevor’s key areas of expertise include geotechnical design and investigations, with a particular interest in forensic investigations, piling, lateral support, deep basements and retaining structures.
Trevor is a Fellow of SAICE and a professionally registered engineer with ECSA. He is also actively involved in developing the profession through the Geotechnical Division, serving in the committee for almost 20-years and as Chairman in 2016 & 2017.