Woods Hc!e Ocsanographic Institution 



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REPORT DOCUMENTATION PAGE 



Form Approved 

 OMB No 0704-0188 

 Exp Date Jun30, 1986 



1a REPORT SECURITY CLASSIFICATION 



Unclassified 



1b. RESTRICTIVE MARKINGS 



2a SECURITY CLASSIFICATION AUTHORITY 



2b. DECLASSIFICATION /DOWNGRADING SCHEDULE 



. DISTRIBUTION /AVAILABILITY OF REPORT 



Approved for public release; distribution 

 unlimited. 



4. PERFORMING ORGANIZATION REPORT NUMBER(S) 



Technical Report CERC-87-17 



5. MONITORING ORGANIZATION REPORT NUMBER(S) 



6a NAME OF PERFORMING ORGANIZATION 



USAEWES, Coastal Engineering 

 Research Center 



6b. OFFICE SYMBOL 

 (If applicable) 



7a. NAME OF MONITORING ORGANIZATION 



6c. ADDRESS (Oty, State, and ZIP Code) 



PO Box 631 



Vicksburg, MS 39180-0631 



7b. ADDRESS (City, State, and ZIP Code) 



8a. NAME OF FUNDING /SPONSORING 



ORGANIZATION 

 US Army Corps of Engineers 



8b. OFFICE SYMBOL 

 (If applicable) 



9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER 



8c. ADDRESS (City, State, and ZIP Code) 

 Washington, DC 20314-1000 



10. SOURCE OF FUNDING NUMBERS 



WORK UNIT 

 ACCESSION NO 

 31616 



11. TITLE (Include Security Classification) 

 Characteristics of Reef Breakwaters 



12. PERSONAL AUTHOR(S) 



Ahrens, John P. 



13a. TYPE OF REPORT 



Final report 



13b. TIME COVERED 

 FROM 



14. DATE OF REPORT {Year, Month, Day) 

 December 1987 



15 PAGE COUNT 



62 



16 SUPPLEMENTARY NOTATION 



Available from National Technical Information Service, 5285 Port Royal Road, Springfield, 

 VA 22161. 



COSATI CODES 



18 SUBJECT TERMS {Continue on reverse if necessary and identify by block number) 

 Breakwaters (LC) 

 Water waves (LC) 



19 ABSTRACT (Continue on reverse if necessary and identify by block number) 



A laboratory study was conducted to determine the stability, wave transmission, wave 

 reflection, and energy dissipation characteristics of reef breakwaters. Reef breakwaters 

 are low-crested structures comprised of a homogeneous pile of stone with individual stone 

 weights in the range of those ordinarily used in the armor and first underlayer of 

 traditional multilayered breakwaters. The study included over two hundred tests, all using 

 irregular wave conditions. 



Results of the study are discussed and summarized through the use of equations fit to 

 the data. The equations fit the data well, are consistent with the physics of the various 

 phenomena as they are currently understood, and approach logical limiting values. 



(Continued) 



20 DISTRIBUTION /AVAILABILITY OF ABSTRACT 

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21 ABSTRACT SECURITY CLASSIFICATION 



Unclassified 



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DD FORM 1473, 84 mar 



83 APR edition may be used until exhausted 

 All other editions are obsolete 



SECURITY CLASSIFICATION OF THIS PAGE 



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