breaking wave depth, wave pressures on a wall may be approximated in the 

 following manner: 



The dynamic part of the pressure will be 



^m - '^ ^ ^ ' C7-85) 



where w is the unit weight of water. If the dynamic pressure is imi- 

 forraly distributed from the Stillwater level to a height h^ above SWL, 

 where h^ is given by 



h^ = 0.78 Hj,, (7-86) 



then the dynamic component of the wave force is given by 



and the overturning moment caused by the dynamic force by 



h 

 I 



2 



^m=^m Ws+-\' C7-8«^ 



where dg is the depth at the structure. 



The hydrostatic component will vary from zero at a height h^ above 

 SWL to a maximum at the wall base. This maximum will be given by, 



P, = w (d, + hj . (7-89) 



The hydrostatic force component will therefore be 



w (d, + h^)^ 

 R, = , (7-90) 



and the overturning moment will be, 



M. = R, ^- = ^— . (7-91) 



The total force on the wall is the sum of the dynamic and hydrostatic 

 components; therefore, 



R, = R^ + R, (7-92) 



and 



M^ = M^ + M (7-93) 



7-159 



