SYNOPSIS

More and more, society requires to know the risk which people, property and the environment are exposed to. The geotechnical engineer should increasingly contribute to reducing exposure to threats, reducing risk and protecting people. The objective of the 55th Rankine Lecture is to convince the profession that one can implement, with benefit, concepts of hazard, risk and reliability to assist in design and engineering recommendations. After a brief overview of basic concepts, the lecture illustrates the advances of hazard, risk and reliability in geotechnical engineering through several "real life" case studies. In these examples, specific engineering questions had to be answered, and the risk and reliability applications provided insight for informed decision-making. The factor of safety remains the main indicator of safety in practice, and its significance and that of key design parameters, such as the characteristic strength, are discussed. The examples come from a wide realm of geotechnical problems, including selection of soil properties, hazard and risk assessment associated with slope stability, tailings dams, offshore installations and code calibration. The contributions of risk assessment and management to geotechnical engineering, the strengths and drawbacks of the approach and emerging issues such as acceptable risk and cascading hazards are discussed. The lecture suggests that interaction with other disciplines helps provide an improved and soundly engineered solution. The geotechnical engineer’s role is not solely to provide judgment on parameters, methods of calculations and resulting safety, but also to take an active part in the evaluation of hazard, vulnerability and risk.


PROFILE OF SPEAKER

Dr. Suzanne Lacasse is a Canadian living in Norway. She is Technical Director at the Norwegian Geotechnical Institute (NGI). She was Managing Director of NGI from 1991 to 2011. Dr Lacasse focused first on laboratory techniques, in-situ testing and soil behaviour modelling studies. She then worked on foundation design, slope stability and the development of calculation procedures offshore. She excelled at combining mathematical and numerical analyses with engineering design in practice. She developed and applied probability, reliability and risk concepts to assist foundation design and decision-making. She has given keynote lectures in 30 countries, and is author of 300 papers. She gave ASCE's 37th Terzaghi Lecture on Offshore Geotechnics (2001) and ISSMGE's 8th Terzaghi Oration on Slope Stability (2013). Dr Lacasse has two PhDs Honoris Causa (University of Dundee and Norwegian University of Science and Technology). She is a member of the US National Academy of Engineers (2001), and received, among others, the Legget Award (Canadian Geotechnical Society) and the 1st MIT Effective Teaching Award in Civil Engineering. She is member of the Royal Society of Canada, the Canadian Academy of Engineers, l'Académie des Sciences Technologies (France), and three Academies of Engineering, Sciences and Letters in Norway. She is Honorary Professor at Zhejiang University, China.