Failure modes and mechanisms for flood defence structures

In order to undertake a flood risk analysis, the performance of different flood defence struc- tures under varying load conditions needs to be represented. This paper reports on work undertaken through the FLOODsite Project (Task 4) in bringing together available information on failure modes for a number of repre- sentative flood defence structure types, to support the development and implementation of system wide models for flood risk assessment. The work comprised a review of structures and failure modes which have occurred in the past, and an investigation of limit state equations and associated uncertainties for both the models and the input parameters. Summaries of all failure modes were combined to create a single reference document; it is hoped that this will be maintained and updated into the future as knowledge on different failure mechanisms evolves. Additional research into selected failure modes and embankment processes was also undertaken and is summarised in this paper, including recommendations as to areas where future research should be focussed.