************** EXAMPLE PROBLEM *************** 

 GIVEN : 



(a) H^ = 8.4 ft , (T = 6 sec.) 



and 



H^ = 9.8 ft . (see previous example) (T = 10 sec.) 



(b) Assume that refraction analysis of the structure site gives, 



Kr =\/— = 0-85 , (T = 6 sec.) 



and 



K^ = 0.75 , (T = 10 sec.) 



for a given deepwater direction of wave approach. See Section 2.3, 

 WAVE REFRACTION.) 



FIND : The deepwater height H^ of the waves resulting in the given 

 breaker heights H^,. 



SOLUTION : Calculate H^/gT^ for each wave condition to be investigated. 



H. 



8-4 rrr. . 



= 0.0072. (T = 6 sec.) 



gT2 (32.2) (6)2 



With the computed value of H2,/gT^ enter Figure 7-5 to the curve for 

 a slope of m = 0.05 and determine H^j/H^^ which may be considered 

 an ultimate shoaling coefficient or the shoaling coefficient when 

 breaking occurs. 



—, = 0.0072 ; — = 1.19 . (T = 6 sec.) 



With the value of H2j/H^ thus obtained and with the value of K/? 

 obtained from a refraction analysis, the deepwater wave height 

 resulting in the design breaker may be found with Equation 7-5. 



Hi, 



H. = T-Vm • l^^-^) 



H^ is the actual deepwater wave height, while H^ is the wave height 

 in deep water if no refraction occurred (H^ = unrefracted, deepwater 

 height). Where the bathymetry is such that significant wave energy 



7-12 



