************** EXAMPLE PROBLEM 5************* 

 GIVEN: The conditions in problem 2. 



FIND: The transmitted height for a submerged thin-wall breakwater with 

 ~~(h - dg) = -1.0 foot. 



SOLUTION : Figure 2 (curve 1) or Figure 4 are used to find H^ = 2.8 feet. 



************************************ 



IV. SUMMARY 



i2 „„j r.r^A^ r^Qlka^'i 



The results of Goda, Takeda, and Moriya (1967)^ and Goda (1969)^ are 

 used to design breakwaters for wave transmission by overtopping. To 

 illustrate the transmission by different types of breakwaters, consider 

 the case where the freeboard is equal to one-half the incident wave 

 height: (h - ds)/ii-i =0.5. The predicted dimensionless transmitted 



height is: 



BREAKWATER TYPE tit/Hi 



Vertical thin wall 0.25 



Vertical B =^ dg 0.20 



Composite dy/dg =0.3 0.30 



Composite d^/dg = 0.5 0.25 



Composite d^/dg =0.7 0.21 



For this condition, the vertical breakwater with a width approximately 

 equal to the depth gives the smallest transmitted wave height; a composite 

 structure gives the largest predicted transmitted wave. 



2G0DA, TAKEDA, and MORIYA, op. cit., p. 5. 

 ^GODA, op. cit, p. 5. 



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