Hatteras National Seashore, which includes the lighthouse, was established in 

 1953 and is managed by the National Park Service (NPS). The Cape Hatteras 

 Lighthouse is located near Buxton, N. C. 



The Problem 



2. It is anticipated that erosion and gradual shoreline retreat will 

 eventually diminish the beach fronting the Cape Hatteras Lighthouse. The US 

 Army Engineer District, Wilmington, (SAW), is providing design expertise to 

 NPS for the development of coastal protection works to safeguard the light- 

 house. The plan of protection selected by NPS consists of encircling the 

 lighthouse with a wave-reflecting seawall fronted by a stone revetment. 



Purpose of the Model Study 



3. The model study was conducted to determine the adequacy of the pro- 

 posed seawall and revetment design and, if necessary, to develop alternate 

 designs from which an optimum plan for stability and economy could be deter- 

 mined. The specific purposes of this investigation were to determine: 



a. The most severe wave conditions relative to stability of the 

 seawall and stone revetment within the limits of still-water 

 levels (swl's)* and wave periods that could be expected to occur 

 in the area of the Cape Hatteras Lighthouse. 



b. The stability and optimum stone size of the rubble stone revet- 

 ment under worst breaking wave conditions. 



c. The distribution of wave forces on the gravity seawall so that 

 it could be designed to withstand their resultant forces and 

 ensure stability against overturning and sliding. 



d. A seawall curvature that would prevent overtopping and minimize 

 the resultant wave forces on the seawall itself. 



e. The combined stability of the seawall and revetment resulting 

 from the hydraulic interaction of the two components. 



* All still-water levels cited herein are in feet mean sea level (msl) 



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