K Armor stability coefficient, as applied in the DHI-Iribarren 

 formula 



K^Q Coefficient of wave transmission by overtopping 



K Layer coefficient 



L Wave length corresponding to the period of peak energy density 



n Number of armor units comprising the layer thickness 



N Armor stability number, as applied in the original Iribarren 

 formula 



Number of waves in a specific model test 

 r Layer thickness 



Statistical correlation coefficient 



R Runup height above still-water level 



S Reserve stability coefficient 

 r ■' 



Sn Dimensionless damage, equivalent to the number of D^cq cubes 



eroded from a cross sectional width of 0^50 



t Time duration of wave exposure 



Tp Wave period of peak energy density 



T Average wave period, derived from a count of "zero crossings" 

 with respect to an arbitrary mean 



T Wave period 



V Flow velocity 



Vol Total armor layer volume per unit breakwater trunk length 



W Weight of a primary armor unit 



WcQ The mean stone weight of a graded sample 



A Armor material density relative to sea water - (p - p )/p 



•^ r w w 



e A parameter of the Extremal Type I and Weibull probability 



distributions 



9 Angle from horizontal of the seaward slope of a breakwater 



X Poisson parameter, denoting the mean number of extreme storms per 

 year 



y Coefficient of static friction 



u Kinematic fluid viscosity 



^ Surf similarity parameter 



p Mass density of the armor material ■ _. 



p Mass density of sea water 



w ■' ■ . 



a Wave directional spreading parameter 



E2 



