Speaker

Dr Suzanne Lacasse, Norwegian Geotechnical Institute (NGI)

Abstract

The Lecture proposes a framework to assist stakeholders in making robust decisions on the safety of civil engineering infrastructure. The proposed risk-informed approach requires: (1) Gathering available information, including field and laboratory data, limit state and performance analyses and assessment of the reliability and significance of the observations and measurements made; (2) Estimating hazards through plausible modes of failure or modes of non-performance and consequences for each hazard (or threat); (3) Preparing a risk picture, or an illustration of the vulnerability and consequences, using qualitative or quantitative risk diagrams and comparing with international risk guidelines and other available experience; (4) Assessing the risk level, identifying the most significant factors for safety and assessing the need for risk-reducing measures; (5) Stakeholder managing the risks through risk-informed decisions on risk tolerability, risk control implementation and risk communication, and (6) Reassessing risk at regular intervals because the risk changes with time. The risk-informed framework aims at understanding uncertainties, quantifying their effect on computed risk and assisting stakeholders in making decisions on risk reduction. The risk-informed approach is compared with the conventional approach to safety and benefits and drawbacks are discussed. The risk-informed approach is illustrated with examples from practice, including the effect of risk mitigation measures on the computed risk. A benefit of the risk-informed decision making is the added insight gained by integrating risk assessment together with the conventional safety evaluation. Risk diagrams are also shown as an effective tool to communicate with stakeholders. The lecture concludes with learnings from case studies and a recommendation of wider implementation of the risk-informed approach in practice.

Dr Suzanne Lacasse, born in Noranda, Québec, did a Bachelor of Arts at University of Montréal and her civil engineering degrees at Ecole Polytechnique of Montréal and MIT. After 12 years on MIT's Civil and Environmental Engineering Faculty, she joined the Norwegian Geotechnical Institute (NGI) in 1982. She was Managing Director of NGI from 1991 to 2012. She is now Expert Adviser at NGI and serves on the GEO Slope Safety Technical Review Board in Hong Kong. She published over 400 papers and gave the Rankine Lecture, the Terzaghi Lecture, the Lumb Lecture, the Coulomb Lecture, the Carrillo Lecture and the Terzaghi Oration. ISSMGE established in her honour the 'Suzanne Lacasse Lecture' on Risk and Reliability in Geotechnical Engineering. Dr Lacasse received five PhDs Honoris Causa from universities in Scotland, Norway and Canada. She is elected member of the national academies of Engineers in the USA, Canada, Norway and France. She is Honorary Professor at Tongji University in Shanghai and at Zhejiang University in Hangzhou, and Advisory Visiting Professor at Jiaotong University in Shanghai. She is Officer of the Order of Canada and a Knight of the First Falcon Order in Iceland.