CASE HISTORIES OF CORPS BREAKWATER AND JETTY STRUCTURES 

 NORTH ATLANTIC DIVISION 



PART I: INTRODUCTION 

 Background 



1. The US Army Corps of Engineers (Corps) is responsible for a wide vari- 

 ety 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 contin- 

 uously subjected to wave and current forces, and they are usually constructed 

 on top of movable-bed materials. Under these conditions structural deteriora- 

 tion 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, due principally to a better under- 

 standing of coastal processes, availability of construction materials, existing 

 wave climates, regional construction practices, and economic considerations. 



Purpose 



2. The purposes of this report are to lend insight into the scope, magni- 

 tude, and history of coastal breakwaters and jetties under Corps jurisdiction; 

 determine their maintenance and repair history; determine their methods of 

 construction; make this information available to Corps personnel; and address 

 objectives of the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) 

 research program. To do this, case histories of Corps breakwater and jetty 

 structures have been developed to quantify past and present problem areas (if 

 any), to take steps to rectify these problems, and to subsequently evaluate the 

 remedial measures. General design guidance can be obtained from those solu- 

 tions that have been most successful. Information in this report should be of 

 particular value to Corps personnel in the US Army Engineer Division, North 

 Atlantic (NAD), and its coastal districts and possibly to non-Corps personnel. 

 Where adequate solutions are lacking or where specific guidance is needed, 



