Geotechnical variability: In the ground and throughout a career

Professor Mark Jaksa

The presentation will cover three aspects of geotechnical engineering research that have been conducted throughout the author’s career and concludes with a brief treatment of the use of physical models in teaching. The first research topic deals with quantifying the large-scale spatial variability of the Keswick Clay in Adelaide by means of undrained shear strength data acquired from several private consulting companies and government departments, incorporating a large number of site investigations. The mathematical technique of geostatistics is used, and it is observed that kriging with a spherical model is able to generate good estimates of the undrained shear strength of the Keswick Clay that can be used for preliminary design purposes. Secondly, the ground improvement technique of rolling dynamic compaction (RDC) is examined in the field and in the laboratory, and numerically by means of artificial neural networks (ANNs). It is observed that RDC is able to improve the ground to depths in excess of 3 m, and the use of transparent soils in the laboratory provides useful insights regarding the influence of RDC on the subsurface profile. In addition, ANNs facilitate the development of reliable models for the prediction of the level of ground improvement due to RDC. The third and final research topic presented involves ground improvement on the Moon. It is a work-in-progress, and early results are presented in this fascinating and exciting endeavour. The paper concludes with a brief treatment of the use of three different physical models used in teaching. It is observed that incorporating demonstrations involving physical models in teaching is helpful for enhancing student learning and engagement.

About the speaker

Prof Mark Jaksa

Professor Mark Jaksa Professor of Geotechnical Engineering, School of Architecture and Civil Engineering, University of Adelaide

Mark Jaksa is Professor of Geotechnical Engineering in the School of Architecture and Civil Engineering at the University of Adelaide, Australia.  He has been an academic for more than 35 years, before which, he spent 4 years practicing as a consulting geotechnical and civil engineer in Adelaide and Canberra in Australia.  He has a Bachelor of Engineering (Honours) degree in Civil Engineering and a PhD, both from the University of Adelaide. He has published more than 230 papers, chapters and reports on various aspects of geotechnical engineering research and teaching.  His primary areas of expertise are in the characterisation of the spatial variability of soils, probabilistic analyses, artificial intelligence, ground improvement, unsaturated soils, lunar geotechnics, and enhancing learning in geotechnical engineering.  He has received several awards recognising his contributions to learning and teaching in geotechnical engineering. Mark is a former Chair of the Australian Geomechanics Society and immediate past Vice-President for Australasia and Treasurer of the International Society for Soil Mechanics and Geotechnical Engineering.  He is also a past Chair of the ISSMGE’s Technical Committee, TC306, on Geo-engineering Education and a member of TC304, on Risk Assessment and Management.

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