(Photos 11 and 12). The structure once again was exposed to the wave and swl 

 conditions of Hydrograph A. By the end of the test, the dolos crown showed 

 major damage with 35 dolosse displaced down onto the harbor-side slope and 5 

 additional crown dolosse had been displaced shoreward but had not moved down 

 onto the harbor-side slope (Photos 13-15). Only one dolos was displaced on 

 the lower lakeside slope. Several dolosse on the upper slope and around the 

 swl and crown exhibited minor to major in-place rocking throughout the test 

 and armor unit displacement did not subside by the end of the test. The 

 hydrograph was not extended since it was thought that damage (dolos displace- 

 ment) already had exceeded a desirable level. Due to the extensive damage 

 accrued during Hydrograph A it was decided that there was no need to expose 

 the section to Hydrograph B. 



17. Prior to the second testing of the 4-ton dolos rehabilitation sec- 

 tion NCB had decided, based on the first testing with Hydrograph A, that the 

 4-ton dolosse was an inadequate design for the 13-4-ft nonbreaking wave con- 

 dition. NCB requested that at conclusion of repeat testing of 4-ton dolosse, 

 WES initiate a test series to determine the actual design level wave height 

 for which the 4-ton dolos showed acceptable stability. 



18. It was noted during the second testing of Plan 1 with Hydrograph A 

 that some of the dolos displacement occurred during impact of the last wave in 

 the wave train produced during a 30-sec test cycle. The wave is typically of 

 a longer period than the rest of the waves due to wave generator effects. To 

 eliminate the possibility of this wave having an influence on the test re- 

 sults, the last wave in the wave train was filtered out in all subsequent 

 tests. 



19. The 4-ton dolos armor was rebuilt and Plan 1 was exposed to 8.0-sec 

 nonbreaking wave heights of 11.0, 11.5, 12.0, and 12.5 ft at an swl of +4.9 ft 

 lwd. The 12.5-ft wave produced damage (dolos displacement) that exceeded an 

 acceptable amount on the breakwater crown. Wave heights below this had caused 

 only minor to moderate damage. The 4-ton dolos armor layers were rebuilt 

 (Photo 16) and the structure was exposed to the wave and swl conditions of 

 Hydrograph C (Table 3). Two dolosse were displaced from the crown onto the 

 harbor-side slope during Step 1. Step 2 caused no dolosse displacement, but 

 two additional crown dolosse were displaced onto the harbor-side slope during 

 the early part of Step 3. All damage had stopped during the last 30 min of 

 Step 3. Steps 1 and 2 caused only minor rocking of a few dolosse at the swl 



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