Discussion. 2b: Hazards

2.4 Lessons re-learnt from the failure of marine structures

R Maddrell

2.5 Hazards to people and propertyfrom wave overtopping at coastal structures

W Allsop

2.6 How far backfrom a seawallUs safe? Spatial distributions of wave overtopping and wave loads on buildings

T Bruce

Discussion to paper 2.4

John Andrews (Royal Haskoning) - Most of the failures described here involve concrete

armour units with high values of the stability factor, KD. DO these failures suggest that

such structures are noticeably more prone to failure than rock armour or concrete

armour units of lower KD?

Reply by R Maddrell

Structures protected by concrete armour units do indeed appear to be more susceptible to damage. This is partly due to the fact that, while they are more hydraulically efficient than rock armour, they rely on their high stability factor and this stability depends on