PART III: WAVE OVERTOPPING INVESTIGATION 

 Testing Procedures 



15. A typical test run for collecting wave overtopping rates took place 

 as follows. Wave gages were calibrated at the beginning of each day of test- 

 ing. The proper signal generation file was loaded into the data acquisition 

 program, and a percent gain was selected. (Percent gain varies the wave 



height H at the wave board without changing the peak period T or 

 mo P 



phasing.) Initial water level readings in the two overtopping containers were 

 recorded, and generation of the wave field was begun. During the following 

 30 min of testing, water from the lower overtopping container was pumped into 

 the upper container, quantified, and released back into the flume as 

 necessary. This procedure minimized the effect that removal of overtopped 

 water might have on swl and wave conditions. When a test was completed, final 

 water level readings were taken, and the water surface in the flume was 

 allowed to still before another test run was started. 



16. The wave gages acquired data at 20 samples per second and, for the 



majority of test runs, wave data and overtopping measurement were collected 



throughout the entire 30-min run. For the range of conditions tested, the 



zero-moment wave height H near the structure varied from about 3.5 to 



mo 



6.0 ft, and the peak period T near the structure varied from about 10.0 to 

 20.0 sec (see Appendixes A and B) . 



17. Stability of the toe armor stone was observed during each over- 

 topping test condition at each of the swl's. Results of the stability tests 

 and overtopping quantities were recorded by an experienced technician, and 

 selected events were documented by still photography and video footage. 



Riprap Stability 



18. In an attempt to control overtopping by restricting the scour depth 

 that influences overtopping, a riprap fronting berm was proposed for the 

 Phase I seawall design at the initiation of the model. The initial proposal 

 by CENAO dictated determination of overtopping rates and stability of riprap 

 toe at the +3.4 NGVD elevation which would have left the riprap unexposed to 

 wave attack (Figure 6a). To adequately determine berm stability, it was 



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