vail J and the ovei-turning moment viould be 25,000 foot-pounds per lineal foot 

 of wall. 



273, The equivalent static expressions at the depth d, are 



P^ s wCh„ - h ) for raaxiiaum pressure at the wall base (614.) 



^s = ^d ^^c " ^^ for total thrust per linear foot of 



2 wall (65) 



^'^s " ^d — ~— — ii ^^^ overturning moment (66) 



The static broken wave pressures, forces, and moments are 1,120 pounds per 

 square foot at the base, 10,100 pounds per lineal foot of wall, and 

 60,500 foot-pounds per lineal foot of wall. 



27ii. Wave Forces . - The preceding computations may be sumjaarized in 

 the following tabulation: 



Table 19 - Wave Pressures, Thrusts and Moments About Wall Base 



Breaker , 

 Period T Height H o Pressure Thrust i4oments 



(seconds) (feet) (lbs. per sq. ft.) (lbs. /ft J (ft. -lbs/ft) 



Dynamic 6,5UO 19,620 235,000 



7 9 



10 



11 11 



Static 



1,060 



8,750 



ii8,000 



TOTAL 





28,370 



2 81;, 000 



Dynamic 

 Static 



ii,860 

 1,090 



16,200 

 9,360 



19U,500 

 52,500 



TOTAL 





25,560 



2li7,000 



Dynamic 

 Static 



223 

 1,120 



1,780 

 10,100 



25,000 

 60,500 



TOTAL 11,880 85,500 



Note that in this case the thrusts and moments are highest for the lowest 

 breaking x-jave heights. 



275. Wall Height . - Though the forces due to the 11-second wave 

 would be far less than those due to the 7 and 9-second waves, the wave 

 crest height above sea level would be greater, "'o prevent significant 

 overtopping, this height would be used for the design wall height. That 

 is, the viall crest would be 8 feet above the still water level, 



136 



