' I II n n 1 1 1 1 1 1 1 1 1 1 n 1 1 1 1 1 1 CONCRETE PLATFORM' 



I l i I l I I I L 



Figure 3 , 



10 20 30 40 50 60 70 i 



DISTANCE ALONG CHANNEL, CM 



90 



100 110 



120 



Cross-sectional view of initial and typical damaged reef profiles 

 (swl denotes still-water level) 



Previous Damage Tests 



12. Previous damage tests were conducted to answer the question of how 

 the breakwater would perform for moderate wave conditions after it had been 

 damaged by very severe wave conditions. For previous damage tests there was 

 very little readjustment of the damage profile from test to test; conse- 

 quently, the breakwater was not rebuilt at the end of a test. No stability 

 information was obtained from these tests, and the duration of wave action was 

 only half an hour; however, wave transmission and reflection were measured. 

 Previous damage tests were performed in the following sequence: 



a. Survey breakwater for last test which becomes initial survey 

 for current test. 



b. Calibrate wave gages. 



£. Select wave file and signal attenuation setting. 



d. Start generator and run waves for half an hour. 



e. Collect wave data (two or three times) . 

 f_. Stop wave generator. 



g_. Survey breakwater as noted above in Step 1. 



13. All 205 of the completed tests of this study can be divided logi- 

 cally into 10 subsets or test series. Because of the test plan, stability 

 test series have odd numbers, and previous damage test series have even num- 

 bers. Table 2 lists the basic information about each subset. 



14. Two different sizes of stone were used during this study. For sub- 

 sets 1 through 6 an angular quartzite with a median weight of 17 g was used, 



