R s = r (§r)(H ) = 0.63(2.05)(3.05) = 3.94 meters (12.93 feet) 



This runup is regarded as the significant runup since it was computed from 

 the deepwater significant wave height. The maximum runup is estimated by 

 multiplying R s by the ratio H max /H s . The value of H max /H s is derived 

 from Table 3 by using the parameters 



K 3 ' 05 = 0.040 



where 



and 



L„ 76.46 



g(7.0) 2 

 L = ~ — — = 76.46 meters (251 feet) 



2tt 



W =1 ' 50 



*o 

 With an offshore slope of 1 on 100, Table 3 shows 



H ; 



Therefore, Stoa's method yields 



Hmax = 1.28 



Rmax = Rs ("If 21 ) = 3.94(1.28) = 5.04 meters (16.54 feet) 



The second method uses equation (8) with the best fit coefficients. To use 

 this equation it is necessary to have the local significant wave height at 

 the toe of the structure, obtained from Table 3 recalling that H /L = 

 0.040, d s /Ho = 1.50, and the slope is 1 on 100. Therefore, from Table 3, 

 H s /Ho = 0.84 and H s = H x K s /H = 3.05(0.84) = 2.56 meters (8.40 feet). 

 Equation (8) gives 



Rs 0.956 = 1>12 



H s 0.398 + (2.56/76.46) 1 /2 (2.5) 

 and 



R s = 1.12 x 2.56 = 2.87 meters (9.42 feet) 

 then 



Rmax = R s (-^ X -)= 2.87(1.28) = 3.67 meters (12.04 feet) 

 where the value for H max /H s was previously determined for Stoa's method, 



22 



