PART II: METHODS FOR ESTIMATING IRREGULAR WAVE OVERTOPPING RATES 

 Shore Protection Manual Method 



Description 



8. The Coastal Engineering Research Center's (CERC's) SPM (1984) 

 possibly presents this country's best known method of estimating overtopping. 

 This method is the result of three different CERC studies; the second two 

 studies extended the method developed in the first study to more design 

 situations. 



9. Saville (1955) reports on overtopping studies conducted at the US 

 Army Engineer Waterways Experiment Station (WES) by CERC in the 1950s. 

 Saville studied overtopping of monochromatic waves by varying the wave char- 

 acteristics, the structure geometry, and the model scale. Interestingly, 

 these tests form the empirical basis for three of the methods discussed in 

 this report. 



10. Weggel (1976) reanalyzed Saville's results in dimensionless form. 

 By looking at the relationships between his dimensionless variables, Weggel 

 derived the following empirical equation for the monochromatic-wave over- 

 topping rate: 



Snono = (s Q o H o ) ex ? 



0.217 . . -1 

 tanh 



(I) 



(1) 



where 



"mono 



Q = volume rate of overtopping, L T 



p 



g = acceleration due to gravity, L/T 



Q*, a = dimensionless empirical coefficients 



H 1 = monochromatic deepwater wave height, L 



F = h - d freeboard above SWL, L 



h = height of structure, L 



d = depth of water at structure, L 



R = runup, L 



An equivalent equation is 



^H.3W 2 f R + F V (0 - 1085/a) , 2l 



Qmono = ( gQ o H o ) {¥^1) (2) 



