units settled causing exposure of underlayer stone between Profiles 4 and 5 

 (Photos A45 and A46). 



Overtopping 



Observations during the experiments showed that overtopping was essentially 

 the same for Plans 1 through 1C and for Plans 2 through 2D, because only the 

 toe stability configuration differed between plans. All Plan 1 series experiments 

 were conducted with 8- and 11 -tonne Core-Locs, and the head portion of the 

 breakwater was +5 m CD. The Plan 2 series of experiments consisted of all 

 11-tonne Core-Locs and the head portion of the breakwater was +8 m CD. 



Overtopping was classified as minor, moderate, or major. Minor overtopping 

 was defined for the present study as occasional or no overtopping. Moderate 

 overtopping was defined as regular overtopping with occasional green water. 

 Conditions that produced frequent overtopping and green water were classified 

 as major. 



The classification of overtopping (minor, moderate, or major) is plotted 

 versus wave condition in Figures 17 through 19. The wave conditions in the 

 figures are labeled from left to right by the sequence in which they were gener- 

 ated during the experiment, i.e., 13-sec, 3.0-m waves were generated first and 

 19-sec, 6.7-m waves were generated last. Figure 17 shows the amount of over- 

 topping that occurred at the trunk for all plans. Major overtopping occurred at 

 the trunk for 16-sec, 6.7-m waves, but was minor or moderate for all other 

 conditions. Figures 18 and 19 show overtopping classifications for Plan 1 and 

 Plan 2 series experiments at the head, respectively. The figures illustrate the 

 reduction of overtopping by raising the crest elevation to +8 m CD (Plan 2 

 series) from +5 m CD (Plan 1 series). 



Summary 



Stability plans tested are summarized in Table 4. Based on experiments con- 

 ducted on the three-dimensional model of Vale de Cavaleiros breakwater, 

 11-tonne Core-Locs are stable on the structure if the toe is stable. It was 

 necessary in the model to simulate a trench having a near vertical face and a 

 depth of 1.5 m. No reduction in stability was observed by raising the +5-m CD 

 portion of the breakwater to +8 m CD. 



Chapter 3 Results 25 



