CASE HISTORIES OF CORPS BREAKWATER AND JETTY STRUCTURES 

 NEW ENGLAND DIVISION 



INTRODUCTION 



Background 



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

 variety 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 

 to provide harbor protection and the safe passage of vessels. These struc- 

 tures are subjected continuously to wave and current forces and usually are 

 constructed on top of movable-bed materials. Under these conditions struc- 

 tural deterioration may occur and, at some point, maintenance, repair, or 

 rehabilitation may be required when the structure deteriorates and/or 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, exist- 

 ing wave climates, regional construction practices, and economic 

 considerations. 



Purpose 



2. The purposes of this report are to provide insight into the scope, 

 magnitude, and history of coastal breakwaters and jetties under Corps juris- 

 diction; determine their maintenance and repair history; determine their 

 methods of construction; and make this information available to Corps 

 personnel. To accomplish these objectives, 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 

 the solutions that have been most successful. Information in this report 

 should be of particular value to the Corps personnel in the US Army Engineer 

 Division, New England (NED), and possibly to non-Corps personnel. Further 



