R.M. Hardy Keynote Address by Dr. Dennis E. Becker
Practical Aspects of Geotechnical Risk Management and Lessons Learned
Effective management of geotechnical risk is a requirement for successful geotechnical engineering design and construction. The presentation provides an overview of geotechnical risk management approaches that are available in state-of-practice, including observational approach, failure modes and effects analysis (FMEA), risk assessments, and reliability and probabilistic methods that are inherently linked to reliability based design (RBD) methods such as Load and Resistance Factor Design (LRFD). All these approaches provide necessary input into risk-informed decision making. The presentation will interrogate the advantages and limitations of these approaches, and how they can be appropriately used in practice. A thorough understanding of credible failure modes and how they develop in structures such as dams, embankments and foundations is a requisite of effective geotechnical risk management towards satisfying project objectives and needs. The important roles of site characterization, rationale design basis, analysis and design are also briefly examined.
Implementation challenges being faced by geotechnical practitioners and lessons learned from projects are identified and discussed.
Dennis E. Becker, Ph.D., P.Eng., FEIC, FCAE - Golder Associates Ltd.
Dennis E. Becker, Ph.D., FEIC, FCAE, P.Eng. is a Principal and Senior Geotechnical Engineer in Golder Associates with 40 years of national and international experience on numerous large scale civil engineering and resource development projects. Dennis is active in many key engineering and professional societies, and maintains close liaison with universities. He serves on technical committees of the Canadian Standards Association (CSA), National Building Code of Canada, Canadian Highway Bridge Design Code and CSA Offshore Code (Foundations), extensively involved with the development and implementation of limit states design (LRFD) for foundations, and was Co-Editor of the 4th Edition of the Canadian Foundation Engineering Manual. He is also involved in the ASCE Geo-Institute’s initiative to produce Guidance Document on Risk Informed Decisions in Geotechnical Engineering. Dennis has received senior awards from the Canadian Geotechnical Society, Engineering Institute of Canada and Canadian Society of Civil Engineers, and is a Fellow of the Canadian Academy of Engineering and Engineering Institute of Canada. Dennis was President of the Canadian Geotechnical Society, Vice-President (North America) of the International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) and Editor of the Canadian Geotechnical Journal.
CGS Colloquium 2020 by Dr. Ariane Locat
Understanding spreads in Canadian sensitive clays
Spreads are one type of large landslides occurring in Canadian sensitive clays. They are characterized by the rapid lateral spreading of a series of coherent clay blocks, having horst and graben shapes, moving on an almost horizontal layer of remoulded clay. Spreads cover large areas (> 1 ha), develop rapidly with no warning signs, and conventional stability analysis do not apply, as they give too large factor of safety when back calculating entire spread. This leaves geotechnical engineers without tools in order to evaluate the risk regarding spreads. For the past decades, Université Laval, Ministère des transports du Québec and Ministère de la sécurité publique du Québec have worked together in order to answer the following question: what are the geotechnical and morphological parameters controlling initiation, propagation and extent of spreads in sensitive clays? This presentation portrays the latest advancement of the research program put in place with the goal to answer this question by integrating detailed field investigation, advanced laboratory testing and analysis and numerical modeling. It therefore presents the state of the art of our understanding of spreads in Canadian sensitive clays, focusing on three aspects: (i) synthesis of spreads in Eastern Canada, (ii) laboratory shear strength characterisation of sensitive clays, and (iii) application of progressive failure to spreads. Although it focuses on sensitive clays, the work presented has important applications to other materials presenting a strain-softening behaviour, such as rock, soft rocks, and snow, for example.
Ariane Locat, ing. Ph.D. - Université Laval
Ariane Locat obtained her Ph.D. in Civil engineering under the supervision of Prof. Serge Leroueil, at the Department of civil and water engineering at Université Laval, and the co-supervision of Dr. Hans Petter Jostad, from the Norwegian Geotechnical Institute. As of 2012, she works as a professor at the Department of civil and water engineering at Université Laval in Québec. Her research mainly focuses on geotechnical characterisation of landslides, understanding mechanical behaviour of sensitive clay and numerical modeling of stresses and deformations during failure of clay slopes.