80 

 70 



EAST HARBOR /^\\ 



Q ' 



60 



- ^° 





50 

 40 



LAKESHORE PARK S \ C -~) 



WINTHROP BEACH (H) 



30 



- y 



WINTHROP BEACH (L) 





HOLLY BEACH Q ' 



• 





• LAKEV1EW PARK, ■ 





70 



_ PRESQUE ISLE (H) ' /caSTLEWOOD PARK . fV 



10 



: 



PRESQUE ISLE (L) / 

 - O CENTRAL BEACH 



I I I I 



I I I 



a> 



0.5 1.0 1.5 2.0 2.5 3.0 3.5 



LsAg 



Figure 28. Dimensionless plot of United States segmented breakwater 



projects relative to configuration (from Pope and Dean (1986)) 



A breakwater design can be evaluated using this method by computing the 

 beach response index for various combinations of breakwater lengths and 

 offshore distances. This method is applied in the case example provided in 

 Appendix B. 



Silvester, Tsuchiya, and Shibano (1980). This method has recently been 

 used in the functional design of headlands at Sims Park, Euclid, Ohio, by the 

 USAED, Buffalo (1986). The spacing and location of the headland break- 

 waters is interrelated as shown on Figure 29, where a is the maximum 

 indentation, b is the headland spacing, Rj and R 2 are radii of the spiral, 6 is 

 the angle between radii R 2 and Rj (where R 2 > Rj), and a is the constant 

 angle between either radius and its tangent to the curve. The ratio of alb is 

 fixed for a given obliquity of incident waves to the headland alignments, /S. 

 Through successive iterations using /?, the spacing and location of the 

 breakwaters can be obtained. Further information is provided in Silvester, 

 Tsuchiya, and Shibano (1980) and Silvester and Hsu (1993). 



48 



Chapter 2 Functional Design Guidance 



