

Table 



4. Computation of 



wave overtopping rates for example p 



roblem 2. 



Reach 



(l) 



d s (ft) 



(2) 



I (ft) 



(3) 

 h - d s 



(4) 

 H b (ft) 



(5) 



H o 



(6) 



<V H 



(7) 



H o/8 T 2 



(8)- 



R 



(9) 



h - d s /R 



(10) 

 a 



(ID 



(12) 

 q 



(13) 

 Q (ft 3 /s) 







t/T = 



1 

 2 

 3 



1.10 



0.60 

 



150 

 165 

 



2.50 

 2.50 



0.86 

 0.50 



0.34 

 0.17 



3.20 

 3.50 



0.0002 

 0.0001 



1.10 

 0.65 



2.27 

 3.80 



1 









 

 





 

 







t/T = 0.125 



1 



2 

 3 



2.35 

 1.85 

 0.50 



150 



200 



80 



1.25 

 1.25 

 1.25 



1.83 

 1.44 

 0.39 



0.95 

 9.69 

 0.13 



2.47 

 3.08 

 3.85 



0.0016 

 0.0019 

 0.0024 



1.90 

 1.14 

 0.23 



0.66 

 1.10 

 5.43 



0.072 



0.04 



0.974 

 

 



73.1 

 

 



73.1 





t/T = 0.25 



1 

 2 

 3 



3.60 

 3.10 

 1.25 



150 

 200 

 170 





 

 



2.81 

 2.42 

 0.98 



1.75 

 1.44 

 0.44 



2.05 

 2.15 

 2.84 



0.0013 

 0.0014 

 0.0018 



3.50 

 2.88 

 0.84 





 

 



0.072 

 0.072 

 0.072 



0.04 

 0.04 

 0.04 



2.63 

 1.96 

 0.33 



197.3 



196.0 



28.1 



421.4 





t/T = 0.375 



1 

 2 

 3 



4.85 

 A. 35 

 2.50 



150 

 200 

 250 



-1.25 

 -1.25 

 -1.25 



3.00 

 3.00 

 1.95 



1.97 

 1.97 

 1.07 



2.46 

 2.21 

 2.34 



0.0016 

 0.0014 

 0.0015 



3.84 

 3.94 

 2.14 



-0.32 

 -0.32 

 -0.58 



0.072 

 0.072 



0.072 



0.04 

 0.04 

 0.04 



8.68 2 



8.45 2 

 9.43 2 



651.0 



845.0 



1,178.8 



2,674.8 













t/T 



= 0.50 (high t 



ide) 













1 

 2 

 3 



6.10 

 5.60 

 3.75 



150 

 200 

 310 



-2.50 

 -2.50 

 -2.50 



3.00 

 3.00 

 3.00 



1.97 

 1.97 

 1.97 



3.10 

 2.84 

 1.90 



0.0020 

 0.0018 

 0.0012 



3.64 

 3.74 

 4.14 



-0.69 



-0.67 

 -0.60 



0.072 

 0.072 

 0.072 



0.04 

 0.04 

 0.04 



39. 70 2 

 62. 00 2 



25. 80 2 





1 No data available. 



2 The values of q are beyond the range of validity of the overtopping equation in the SPM 

 (h - d_/R < 0); they probably overpredict the overtopping rate by a large amount as h - d s /R 

 becomes much less than 0. 



The total overtopping rate for the reach corrected for angle of 

 approach is given in column 13. For the example, Q = q£= £q cot 

 = 0.5q£ since a = 45° and t = weir-crest length for the reach. 



wave 



2 „ 



*************************************** 



In example problem 2, the overtopping equation (eq. 10) was used for 

 conditions beyond its range of validity since it was used to compute q for 

 cases where (h - d g )/R is less than zero. The overtopping rates for t/T 

 = 0.375 and t/T = 0.50 are therefore probably too high. At present there is 

 little or no information available to predict overtopping when (h - d„)/R is 

 less than zero. It seems reasonable to expect overtopping rates to continue 

 to increase for values of (h - d g )/R slightly less than zero; however, as 

 (h - d g )/R approaches d g /R (i.e., as h ■* 0), the overtopping rate must 

 approach zero. 



34 



