FIND : The height above SWL to which the structure must be built to 

 prevent overtopping by the design wave. 



SOLUTION : The wave height must be converted to a deepwater value. 

 Using the depth where wave height was measured, calculate 



30 



L gT2/27r (32.2/2Tr)T2 5.12(8)2 



— = 0.09155 



To determine the shoaling coefficient, H/H' Table C-1 in the 



SPM is used, and 



Therefore, 



— % 0.9406 



H 



Calculate, also. 



H' = 

 '° 0.9406 0.9406 



H^ = 8.5 feet (2.6 meters) 



^■^ = 0.00412 



gT^ 32.2(8)2 



and, for d„ = 25 feet 



25 



=2.94 



The bottom slope is very gentle (1 on 90). Assuming that the 

 slope approximates a horizontal bottom, the appropriate set of 

 curves for dg/H^ = 2.9 is Figure 2 (for dg/H^!, = 3). For a 1 on 



26 



