d,a= 0.38 m 



"i ^ h^ 100 0:0.67 



0.5 



O.A - 



0.3 



0.2 



0.0001 



T 1 1 — I — r-r-r 



-1 1 r 



P:Porosity {assumed tobethesomefor 

 core ) 



Depth Limited 

 V.'yve Height 



"Is/ 



d/gT': 0.0058 



I I I I I 



0.0002 



0.0004 0.0006 0.00 1 

 H/gT^ 



0.002 



0.004 0.005 



Figure 38. Example of the influence of porosity on the predicted 



coefficient of transmission for a rubble-mound breakwater, 



0.9 



0.8 - 



0.7 



0.6 



0.5 



0.4 



0.8 





1 1 



1 







1 



f- 



- 



^^ 



^ 







^ 



- 



~ 



fl 479 



.^ 









" 





/^ 



- 



A/ 



/r 









- 



- 



/ y 











- 



— 













_ 





/ ^ 



uboeriol 



Si 



bmer^ 



ed 







1 1 



J..., 







1 



1 



0.9 



1.0 

 ds/h 



1.2 



Figure 39. The relative importance of transmission by overtopping 

 as a function of the incident wave height and the water 

 depth-to-structure height ratio (after Saville, 1963). 



51 



