Discussion. 7b: Breakwater Design and Analysis

7.4 Optimum safety levels for breakwaters

H. F. Burcharth & J Sorensen, Aalborg University, Denmark

7.5 Tiered reliability-based methods for assessing the performance of coastal defences

F. Buijs

1.6 Monitoring and maintenance of coastal structures

D. Phelp

1.1 Composite-berm rubble mound breakwater

J. Melby

Discussion to Paper 7.4

Chris Brown (Consultant) -You make the point that it cost very little more to provide an extrafactor ofsafety. Some 20 years or so ago when preparing a designfor the Eden Breakwater in New South Wales (Australia), wefound that the cost ofproviding limit stateprotection to the breakwater was only 4% more expensive than designingfor clients nominated 1:50 year event (but using a stability coefficient 17% lower than for limit state analysis. This offered the notionalprospect ofa very low maintenance structure ofindefinite life.