Applying the reduction of Equation 7-103 for the angle of wave approach, 

 with 



R' = R^ sin2 a = 16,900 (sin 80° )2 , 



R' = 16,900(0.985)2 = 16,400 Ibs./ft. 

 Similarly, 



M' = M^ sin^ a = 126,800 (sin 80°)^ , 



lb. -ft. 

 M' = 126,800 (0.985)2 = 123,000 — — . 



ft. 



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

 the wall makes with the vertcal is, 



d = arctan (10) « 84° . 



Applying Equation 7-104, 



R" = R' sin^ d = 16,400 (sin 84°)^ , 



R" = 16,400 (0.995)2 = 16,200 Ibs./ft. 

 Similarly for the moment, 



M" - M' sin2 6 = 123,000 (sin 84°)^ , 



M" = 123,000 (0.995)2 - 121,800 -^' . 



ft. 



The total force and overturning moment are given by the sums of the 

 reduced dynamic components and the unreduced hydrostatic components. 

 Therefore, 



Rj = 16,200 + 4,400 = 20,600 Ib./ft., 



Ib.-ft. 

 M, = 121,800 + 17,100 = 138,900 — — . 

 ' ft. 



7.37 STABILITY OF RUBBLE STRUCTURES 



7.371 General . A rubble structure is composed of several layers of 

 random-shaped and random-placed stones, protected with a cover layer of 

 selected armor units of either quarry stones or specially shaped concrete 

 units. Armor units in the cover layer may be placed in an orderly manner 



7-167 



