Objectives of Report 



A properly designed detached breakwater project can be a viable option for 

 shoreline stabilization and protection at certain coastal sites. The objectives of 

 this report are to summarize and present the most recent functional and struc- 

 tural design guidance available for detached breakwaters, and provide exam- 

 ples of both prototype breakwater projects and the use of available tools to 

 assist in breakwater design. 



Chapter 2 presents functional design guidance including a review of 

 existing analytical techniques and design procedures, pre-design site analyses 

 and data requirements, design considerations, and design alternatives. 

 Chapter 3 discusses numerical and physical modeling as tools for prediction of 

 morphological response to detached breakwaters, including a summary of the 

 shoreline response numerical simulation model GENESIS. A summary of 

 moveable-bed physical modeling and modeled breakwater projects is also 

 presented. Chapter 4 summarizes and presents structural design guidance 

 including static and dynamic breakwater stability and methods to determine 

 performance characteristics such as transmission, reflection, and energy dissi- 

 pation. Other breakwater design issues are discussed in Chapter 5 including 

 beach fill requirements, constructability issues, environmental concerns, and 

 project monitoring. Chapter 6 presents a summary and suggestions for the 

 direction of future research relative to detached breakwater design. Appen- 

 dix A provides a case example of a breakwater project designed and con- 

 structed at Bay Ridge, Maryland, including GENESIS modeling of the project 

 performance. Parameter definitions used throughout the report are given in 

 Appendix B. 



Chapter 1 Introduction 



11 



