Maximum Monochromatic Uaue Condition 

 Uater Depth = 4.0 ft 



— 6-ft Flume 



2.0 



1.5 - 



1.0 



0.50 - 



0.0 



4 6 8 



Uaue Period - T (sec) 



Figure 4. Wave generating capability of 6-ft fiume 



Association of Hydraulic Research (lAHR) Conference in 1986 (Dette and Uliczka 1986), the Cocistal 

 Sediments Conference in 1987 (Dette and Uliczka 1987), and the 21st International Conference on Coastal 

 Engineering (Uliczka and Dette 1988). The purposes of their prototype-scale tests were to investigate dune 

 recession and beach erosion to aid in the development of numerical models and to determine appropriate 

 time scales for these phenomena. 



77. The sand in the prototype experiments had a median diameter of 0.33 mm and was representative 

 of sand found on the North Sea coast of West Germany. Approximately 1,000 m^ of this sand was placed 

 in front of a concrete structure with a slope of 1 on 4. The sand was molded to the same initial slope as the 

 concrete structure shown in Figure 6. For the regular wave tests, monochromatic waves with a height of 

 1.5 m and period of 6.0 sec in water depth of 5.0 m were used to erode the initial profile. As many as 



80 waves were generated at a time; then the wave machine was stopped and profiles were measured. Stops 

 were made whenever the wave height variation (due to reflections) reached ±20 percent of the originally 

 generated wave height. The experiment was continued until little or no change was observed in profile 

 development, indicating the equilibrium profile had been obtained. 



78. The regular wave prototype test is somewhat unique because of the exposure of the concrete 

 revetment during profile adjustment. Not many prototype-scale movable-bed tests have been conducted, 

 and this test represents one of the few cases where development of a movable bed adjacent to a hard 



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