*************** EXAMPLE PROBLEM 37 ************** 

 GIVEN: A structure in water, dg = 2.3 m (7.5 ft) , on a 1:20 nearshore 



slope, is subjected to breaking waves, Hj, = 2.6 m (8.4 ft) and period T = 

 6 s . The angle of wave approach is, a = 80°, and the wall has a shoreward 

 sloping face of 10 (vertical) on 1 (horizontal). 



FIND ; 



(a) The reduced total horizontal wave force. 



(b) The reduced total overturning moment about the toe (Note: neglect the 

 vertical component of the hydrostatic force). 



SOLUTION: From the methods used in Example Problems 34 and 36 for the given 



wave conditions, compute 



and 



R^ = 250 kN/m (17,100 lb/ft) 



M = 575 i^^^ (129,300^^ ) 

 m m ft 



R = 65 kN/m (4,450 lb/ft) 

 s 



M = 78^^^:^(17,500^^) 

 8 m ft 



Applying the reduction of equation (7-112) for the angle of wave approach. 



with R = R 



m 



R' = R sin^ a = 250 (sin 80°)^ 



m 



R' = 250 (0.985)^ = 243 kN/m (16,700 lb/ft) 



Similarly, 



M' = M sin^ a. = 575 (sin 80°)^ 

 m 



M' = 575 (0.985)^ = 558 ^^=^ (125,500 ^^i^) 



m ft 



Applying the reduction for a nonvertical wall, the angle the face of the 

 wall makes with the horizontal is 



e = arctan (10) « 84° 



Applying equation (7-113), 



R" = R'sin^e = 243 (sin 84°)^ 



7-201 



