analytical predictions by scale model tests. Nevertheless, analytical proce- 

 dures are available for prediction of armor unit hydraulic stability (resis- 

 tance to displacement by waves), armor layer damage rates, and breakwater wave 

 transmission characteristics. These tools, with laboratory verification, can 

 be used to systematically select an optimum alternative. 

 The proposed procedure 



110. A systematic optimization procedure has been proposed which makes 

 use of the analytical tools currently available to coastal engineers for 

 rubble-mound breakwater design. The procedure begins with definition of the 

 site conditions and formulation of an ensemble of alternative design criteria 

 pairs. These steps are followed by estimates of first costs, maintenance 

 costs, and user costs with the breakwater in place for each alternative. The 

 concept of statistical expectation is applied to measure the costs of all al- 

 ternatives on the same basis. The process is concluded by physical model 

 tests to verify the analytical predictions for structural stability and wave 

 transmission characteristics of the apparent optimum alternative. The entire 

 procedure is summarized in Table 8, with references to pertinent formulae, 

 software, and documentation. 



Table 8 

 Summary of Optimization Procedure 



Step 



Procedure 



1 



Define site 





conditions 



2 



Estimate economic 





losses without 





breakwater 



Formulate an en- 

 semble of alterna- 

 tive functional and 

 structural criteria 

 pairs 



Pertinent 

 Equations and Tables 



Equations 19* or 22* 



Equations 31* and 32' 



Table 6 



Available 

 Software 



WAVDIST (WES, 

 CERC (in 

 preparation) ) 



BWLOSSl (WES, 

 CERC (in 

 preparation) 

 and Appendix A) 



(Continued) 



Mote: * indicates the equations which are applied in the referenced 

 software. 



70 



