Figure 14, Fill ratio versus groin spacing/length ratio 



groins spaced at 450 ft. The width-to-length ratio of this alternative (1 .6) and the 

 length of the structures (280 ft) are consistent with the empirical evaluation of 

 groin performance. 



Relationships derived from this empirical analysis were consulted to direct 

 the design of proposed structures. Proposed groins will be constructed with 

 lengths on the order of 300 to 400 ft and with width-to-length ratios of approxi- 

 mately 1.5. The design parameters identified here are not considered rigid design 

 requirements. Instead, the performance measures of existing groins serve as 

 guidance in conjunction with sound engineering analysis and judgment towards 

 development of a recommended design. 



GENESIS Simulation of Physical Model Results 



GENESIS has been successfully applied in numerous evaluations of shore- 

 line change associated with beach fills and coastal structures (e.g.. Hanson, 

 Cravens, and Kraus 1988). In the present study, GENESIS capabilities for 

 modeling shoreline response to multiple straight and T-head groins were evalu- 

 ated by replication of movable-bed laboratory experiments. Kraus (1983) 

 modeled the response of the shoreline to a single detached breakwater in a 

 physical model with the predecessor model to GENESIS. Hanson and Kraus 



Chapter 3 Functional Design 



15 



