1F= 1.46 



Therefore 



calculate 



H^ = 1.46 (1.5) = 2.2 m (7.2 ft) 



% 2.2 



gT^ (9.8) (8)^ 



= 0.0035 



Then from Figure 7-2, from the curve for m = 0.05 



= 0.95 



% 



and 



d^ = 0.95 Y^ = 0.95 (2.2) = 2.1 m (6.9 ft) 



Therefore, the wave will break a distance (2.1-1.2)70.05 = 18.0 m (59.0 ft) 

 in front of the structure toe. 



The runup value calculated above is a first approximation of the actual 

 runup and is used to calculate a hypothetical slope that is used to 

 determine the second approximation of the runup. The hypothetical slope is 

 taken from the point of maximum runup on the structure to the bottom at the 

 breaker location (the upper dotted line on Figure 7-22) . Then 



Ax = 18.0 + 9.0 + 6.0 + 9.0 = 42.0 m (137.8 ft) 



and, the change in elevation is 



Ay = 2.1 + 4.8 = 6.9 m (22.6 ft) 



therefore 



^ _ Ax (42.0) , , 

 cot = — - = \ ( = 6.1 

 Ay (6.9) 



This slope may now be used with the runup curves (Figs. 7-10 and 7-11) to 

 determine a second approximation of the actual runup. Calculate d /H' 

 using the breaker depth dj, 



^^ 2.1 , ,. 

 Interpolating between Figures 7-10 and 7-11, for 



% 



= 0.0024 



ST^ 



gxves 



R 



= 1.53 



7-38 



