Development of an approach to evaluate the failure probabilities of river levees based on expert judgement: Application to a case study

Studies carried out to analyse the risks of levees must include an evaluation of the probabilities of occurrence of different failure mechanisms. The probabilistic quantitative evaluation of these mechanisms remains difficult due to often insufficient data, the natural variability of the materials, structures that are very long, and the unavailability of mechanical models for certain failure mechanisms. This makes it necessary to call for expert judgement to evaluate the probabilities of failure. However, expert judgement generally has qualitative and subjective dimensions, and it includes biases that are liable to impair the capacities of an expert to elicit their evaluations. This article proposes an approach to processing expert judgement that includes the modalities of I ndividual e xpert E licitation, C alibration, A ggregation, and D ebiasing of expert judgement ( IeCAD ). This IeCAD approach has been developed for river levees in view to correcting biased expert evaluations in the case of evaluating the failure probability of structures.