0.8 - 



0.6 - 



0.4 - 



0.2 - 



SWL- 



Wave Type 



• Monochromotic 

 o Irregulor 



J I I I I 



J I I I L 



BWl 



0.006<d/gT2<0.03 

 B/h : 0.4 



• • • 



-0.8 -0.6 -0.4 -0.2 0.2 0.4 0.6 O.i 



F/R 



1,2 



1 1 \ r— 1 1 1 1 1 r 



T — -| — I — r 



Lomorre (19671 

 d/gT2<0.03 

 0.l8<B/h <0.22 



1.2 



13. Wave transmission coefficients for smooth 



impermeable breakwaters with 1 on 1.5 slopes. 



breakwater crest width-to-structure height ratio of B/h = 0.4. The lower part 

 of the figure gives test results from Lamarre (1967) , who tested structures 

 with smaller values of B/h. Although there is some scatter in these data sets, 

 it appears that the wave transmission coefficient decreases approximately 

 linearly as F/R increases and that this linear trend is found for submerged 

 as well as subaerial breakwaters. Most of the scatter occurs where the crest 

 elevation is at the Stillwater level (F/R = 0) for BWl, with small waves having 

 significantly lower wave transmission coefficients than are present in the 

 linear trend. Fortunately, small waves are generally not of interest for design 

 purposes. The few irregular waves tested with BWl suggest that wave transmission 

 coefficients for irregular waves follow the same trend as for monochromatic 

 waves. The mean wave height, taken as 63 percent of the significant wave height, 

 should be used in equation (12) to determine the effective runup for predicting 

 wave transmission coefficients for irregular wave conditions. 



29 



