Comparison of methods 



52. Using the design relationships presented in Part II, the Lakeview 

 Park project has been used to intercompare relationships and further assess 

 their validity. This project was chosen for use because it is representative 

 of US projects, has been successful in protecting the project beach, and has 

 already been designed using the JMC and Diffraction Energy Methods. Recom- 

 mended project parameters using Toyoshima's (1972, 1974) median-depth system 

 were also calculated for comparison. Linear wave theory was used to bring 

 deepwater waves to the structure, and the structure depth using Toyoshima's 

 method was the same as the as -constructed depth. The various design parame- 

 ters resulting from each method are presented in Table 2. 



Table 2 

 Lakeview Park Structural Parameters Corresponding to Design Method 



Method L^, m -^g- ■" X, m d , m L^/X 



Diffraction ~76 49 73 3.5 1.04 



Energy 



(as constructed) 



JMC 40 23 39 1.6 1.03 



Toyoshima's Median- 60 24 18-40 3.5 1-3.3 



Depth System 



53. The JMC method resulted in a smaller structure length, gap dis- 

 tance, and distance offshore from the original shoreline as compared with the 

 as -constructed parameters. Toyoshima's median- depth system resulted in a 

 larger segment length and gap distance than the JMC method, but distance off- 

 shore was equal to or less than the other two methods. The range in recom- 

 mended structure distance offshore is quite large using Toyoshima's method. 

 Using values of the structure length-to-distance offshore ratios for each 

 method with the predictive relationships discussed in Part II (also illustrat- 

 ed in Figure 10) , the most likely morphological response corresponding to each 

 method can be predicted. The majority of the relationships indicate that the 

 most likely beach response for all three methods would be tombolos. However, 

 the morphological response in the prototype is salients. 



36 



