Fragility Curves for Analysis of Levees Subject to Concentrated Leak Erosion

This paper discusses the use of fragility curves as a way of expressing the likely performance or reliability of a levee, as part of a flood risk systems analysis and/or to support asset specific decision-making. In terms of geotechnical mechanisms, the focus of the paper is on concentrated leak erosion, the form of internal erosion believed to be most relevant to UK levees. The paper discusses the use of fragility curves combined with asset-specific extreme loading distributions to determine a national database of asset annual failure probabilities as a one means of prioritizing future detailed inspections, investigations and interventions.

Keywords: Fragility curve, flood risk, under-seepage piping, concentrated leak erosion, prioritization.