Understanding the way in which flood defence structures perform under varying hydraulic load conditions, and ultimately how they may fail, is critical for undertaking flood risk assessments and in supporting effective asset management. 

The purpose of the research under Task 4 was:

• To gather existing information on defence failure mechanisms, and
  
  
• To extend knowledge in a number of critical areas through review and detailed analysis of specific structure failure modes using hydraulic model testing and numerical modelling.

The work addressed ‘flood defence structures’ and hence covered a wide range of different structure types, such as flood embankments, revetments, concrete walls, sheet piling, etc.

Task 4 produced a report collating and describing the failure mechanisms for a wide range of generic flood defence structures.  It includes a definitive listing of reliability equations for the failure mechanisms for use in system modelling of flood risk.  FLOODsite report T04-06-01 “Failure Mechanisms for Flood Defence Structures” can be accessed by clicking on the button “Publications Currently Available Online” below.

The research in Task 4 links closely with work under Task 6 where a more detailed review of breaching processes and modelling capabilities for embankments was undertaken.  This work also provided input into the reliability analysis method development undertaken by Task 7.