greatest interest, so the primary emphasis of this analysis is on the highest 

 15 percent of wave crests in a wave train. The variable p is used to desig- 

 nate the probability level of exceedance of interest. For example, (n ) 



*^ c'p=o. 05' 



p = 0.05, indicates that 5 percent of the crest elevations 



ric. 



where the subscript 

 exceed the value of 



Assumed independent variables are significant wave height, Hg (defined as 

 four times the rms water level, tij^g), period of peak energy density, !„, 

 water depth, d, and beach slope, m. 



1. Irregular Wave Crest Elevations . 



Figure 16 presents several irregular wave records illustrating various 

 amounts of nonlinear ity. Records A and B have crests which are slightly larger 

 than half of their zero up-crossing wave heights; record C has crest elevations 

 which are a large fraction of wave height. Table 6, which is a compilation of 

 selected wave record results, indicates the elevation of maximum crests for 

 various water depth, significant wave height, and period of peak energy density 



2 - 



2 - 



d/glp-^ = 0.025 Hs/glp"^ = 0.0063 



Hs/d = 0.25 



d/gTp2 = 0.017 



Hs/gTp - 0.0035 



Hc/d = 0.2l 



B 



d/gTp2 = 0.0041 Hs/gTp2 3 0.00106 Hs/d = 0.26 



Figure 16, Sample of irregular wave time histories. 



30 



