10 



— 



1 



^ 



,„„„„ 

















Force (Ib/f 



on c 



o c 

 o o c 





, 



'^^^^ 











- 



— -' 





/ 









~" 























1 1 

 Concrete Sheet-Pile Groin- 



k^ 







^S^^- 

















^% 



















sw 



/L 







^^ 



\ 









Beac 



ti Profi 



K 



^ 























^^WWMM^ 



^^^^»J5 



mw 



-15 

 -300 -200 -100 



100 200 300 400 500 600 700 

 Distance from Shoreline ( ft ) 



Figure 7. Loading on windward side of groin. 



As a check on the wave force when the trough is at the structure, the 

 hydrostatic force can be computed using the minimum water surface eleva- 

 tion. From SPM Figure 2-13, the value of (Yj^ - d)/H + 1 is found to be 

 0.850 where ^^ is the height of the wave trough above the bottom. 

 Therefore, 



y, -d 



+ 1 = 0.850 



rearranging and solving for y^^. 



y^. = (0.850 - 1.0) H + d 



y^ = -0.150 (7.8) + 10 = 8.83 feet (2.69 meters) 



Computing the hydrostatic pressure 

 2 



"^t 64(8.83)^ „ ,„, , . , 



F = — — - = ^t; — = 2,495 pounds per foot or 



t 2 2 y f f 



36,400 newtons per meter 



compared with F^ = 2,400 pounds per foot for the value computed from the 

 Miche-Rundgren figures in the SPM. 



15 



