39. The values presented in Table 1 are for simple (plane in cross 

 section) seawalls. Owen also investigated overtopping of seawalls with large 

 berms. The SPM (1984) refers to this type of cross section as a composite 

 slope. The results are presented in Owen (1980) in the form of different A 

 and B values . 



40. In order to interpolate between seawall slopes, Owen (1980) plots 

 A and B values for all the situations investigated. Owen goes a step 

 further and generates dimensionless design curves for each berm situation 

 tested. Figure 13 is the design curve for simple seawalls. 



o- 2 



zZ 



i 



l l l 



= 0.02 



1 1 1 





~7fn4 



~-~^r~^^^~~~~^~-------. ~ z 





0.06 





0.08 





0.10 



3 





0. 12 " ■ __ — 







0. 14 ■ — ~_ "— — _ 







a 16 — — _ --^ ~~--^ 









0.18 -~^_ -^ ~"-^ 



^^^~^^S^^^^^- 







0.20 — ■ -^ «^ ^*» 







0.22 ' ^ ^^ ^-^ ' — >. 



10"" 







0.24 ""^-^""^s^^^ """\ "* 



XN/N. 





^ 







n^v^n. ^s. = 













4|sNX\\\\ 



\. N. \. \v ^s^ 







icr 6 



— 





^^H^ 



\\\\/\ >v : 



10 •' 





l 



i i WW 



\\ \ \i \ \i \ 



SEAWALL SLOPE 



Figure 13. Owen's dimensionless overtopping for smooth, 

 plane-sloped structures (from Owen 1980) 



Example 5 



41. Using Owen's method, an estimation can be made of the volume rate 

 of water which will overtop a 15-ft-high, 1:3-slope, smooth seawall in 10 ft 

 of water. Wave height and period are H = 5 ft and f = 8 sec. 



TVgH~ [8>/3272(5)] 



= 0.049 



(21) 



23 



