and 



R = 3.4 (H') = (3.4) (1.5) = 5.1 m (16.7 ft) 



* 

 The values of a and Q for use in equation (7-10) can be found by 



interpolation between Figures 7-25 and 7-26. From Figure 7-26, for small- 

 scale data on a 1:3 slope 



a = 0.09 I d H' 



r at -I- = 2.0 and -Ar = 0.0024 

 * I H 2 



Q = 0.033 ) o gT 



Also from Figure 7-26, for larger scale data 



a = 0.065 



Q = 0.040 

 o 



d H' 



^ at -5I- = 2.33 and -^ = 0.0028 

 ^o gT^ 



Note that these values were selected for a point close to the actual values 

 for the problem, since no large-scale data are available exactly at 



^=2.0 

 o 



gT 



= 0.0024 



From Figure 7-25 for small-scale data on a 1 on 1.5 slope 



a = 0.067 1 d H' 



^ [ at -nl = 1.5 and -^ = 0.0016 

 Q = O.OI35J o gT 



Large-scale data are not available for a 1 on 1.5 slope. Since larger 



* 

 values of a and Q give larger estimates of overtopping, interpolation 



by eye between the data for a 1 on 3 slope and a 1 on 1.5 slope gives 



approximately 



a = 0.08 



Q = 0.035 



From equation (7-10) 



"^ ta„h-' ^ 



7-56 



