60.0 7.0 80.0 
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0.0 30.0 
TUT AT 
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MAXIMUM RECESSION (FT) 
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TUTTI 
RECURRENCE INTERVAL (YEARS) 
CASE D: PROFILE NO.186 HURRICANES AND NORTHEASTERS 
Figure 39. Maximum recession-recurrence design curve for combined 
hurricanes and northeasters for Profile 186 
Evaluation of Alternative Beach Fill Designs 
171. The beach erosion model with seawall modification was used to 
evaluate the effectiveness of the three alternative beach fill designs. The 
basic berm and profile configuration, shown in Figure 25, is as follows: 
Berm height of 10.0 ft MLW 
Seawall fronted by berm widths of 30, 50, and 100 ft 
Berm slope of 1:10 to MLW 
Offshore slope (from MLW) of 1:35 
The design wave height was taken to be 12 ft, a representative maximum value 
Io |p 
1a 10 
for the coast (Table 1). The shape parameter for the design beach fill should 
be selected to be representative of a wide beach area (such as Case C or D), 
not one controlled by a seawall as in Case B. Survey data for Cases C and D 
indicate a mean sediment diameter in the range of 0.28-0.34 mm. Calculations 
of the shape parameter for the 1:10 and 1:35 slopes adjusted to MSL resulted 
in a value of 0.149 m'/3, corresponding to a mean diameter of approximately 
0.31 mm. Since this value is consistent with the 1953 and 1985 surveys, it 
92 
