CASE HISTORIES OF CORPS BREAKWATER AND JETTY STRUCTURES 

 SOUTH ATLANTIC DIVISION 



PART I: INTRODUCTION 



Background 



1. The US Army Corps of Engineers (Corps) Is responsible for a wide va- 

 riety of coastal structures located on the Atlantic, Pacific, and gulf coasts, 

 the Great Lakes, the Hawaiian Islands, other Islands, and inland waterways. 

 Coastal improvements such as breakwaters or jetties are necessary where safe 

 harboring or passage of shipping is required. These structures are continu- 

 ously subjected to wave and current forces and are usually constructed on top 

 of movable-bed materials. Under these conditions structural deterioration can 

 occur and, at some point, maintenance is required if the structure fails to 

 serve the existing needs of the project. Some of these projects have been 

 maintained for 150 years or more. Methods of construction (and repair) have 

 varied significantly during this time, principally because of a better under- 

 standing of coastal processes, availability of construction materials, exist- 

 ing wave climates, regional construction practices, and economic considerations, 



Purpose 



2. The purposes of the case histories of Corps breakwater and jetty 

 structures are to lend insight into the scope, magnitude, and history of 

 coastal breakwaters and jetties under Corps jurisdiction, to determine their 

 maintenance and repair history, to determine their methods of construction, to 

 make this information available to Corps personnel, and to address objectives 

 of the Repair, Evaluation, Maintenance and Rehabilitation research program. 



To accomplish these objectives, case histories have been developed to quantify 

 past and present problem areas (if any) , to take steps to rectify these prob- 

 lems, and to subsequently evaluate the remedial measures. General design 

 guidance can be obtained from those solutions that have been most successful. 

 Information in this report should be of particular value to Corps personnel in 

 the US Army Engineer Division; South Atlantic (SAD) , and its coastal districts 

 and possibly to non-Corps personnel. Where adequate solutions are lacking or 

 where specific guidance is needed, further research will be conducted to 

 address these problems (e.g. general armor stability, toe protection, local- 

 ized damage, use of dissimilar armor, wave runup and overtopping). 



