K = — ^^ = — (c . - eg- 



The experimental observations and measurements are used to validate this incipient 

 motion criterion for breakwater armor. 



In Chapter 3, historical damage experimental techniques, measurements, 

 and models are described for rubble mound breakwaters. It is noted that there are 

 inconsistencies in both historical and recent modeling techniques which have a large 

 effect on the conclusions drawn. In particular, different methods of computing eroded 

 area or volume produce results that differ by nearly a factor of 2. Several authors have 

 made note of the fact that irregular wave experiments may not produce an equilibrium 

 profile prior to failure. This conclusion was verified within this study. Many 

 breakwater stability experiments have been conducted; but nearly all tests were 

 conducted with nonbreaking waves, started with an undamaged structure, and 

 progressed to relatively low levels of damage. 



Chapters 4-7 discuss a new experiment to investigate damage development 

 on a breakwater exposed to a series of depth limited storms of varying wave energy and 

 in varying water levels. It is noted that this study was motivated by the fact that no 

 general irregular-breaking-wave damage progression experiments have been conducted. 

 Therefore, no generally applicable relations exist that would permit prediction of 

 damage progression in breaking waves. A methodology is developed for measuring 



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