SUMVIARY OF FACTORS RELATED TO FUNCTIONAL PUNNING 66 



3. rUNCnONAL PLAiNlNING OF PROTECTIVE MEASUltBS 

 Introduction 



66 



SEAWALLS, REVETMENTS AND BULKHEADS 66 



Functions 66 



Limitations 68 



Functional Planning of the Structure 68 



Use of the Structure 68 



Location of Structure with Respect to Shore Line 6? 



Length of Structure 69 



Height of Structure 69 



Determination of Ground Elevation before the Wall 70 



PROTECTIVE BEACHES 73 



Functions 73 



Limitations 73 



Tidal Zone Slopes Ih 



. Size of Beach Fills 7h 



Size of Feeder Beach 76 



Sand Dunes 76 



GROINS 77 



Definitions 77 



Theory of Groin Operation 77 



Purpose 80 



Limitations on the Use of Groins 80 



Permeability of Groins 81 



High and Low Groins 8l 



Adjustable and Fixed Groins 8l 



Dimensions of Groins 82 



Spacing of Groins 83 



Length of Groin 85 



Alinement of Groins 89 



Order of Groin Construction 90 



OFFSHORE BREAKWATERS 90 



Use 90 



Effect on the Shore Line 90 



Operation of an Offshore Breakwater 92 



Offshore Breakii/ater in Series 9h 



Height of Offshore Breakwater 9h 



Submerged Breakwaters 9h 



Exposed Breakwaters 97 



Length and Distance from Shore 97 



Spacing of Offshore Breakwaters 97 



