toe berm armor stability. Some of tbese parameters are discussed in Brebner 

 and Donnelly (1962) and Tanimoto, Yagyu, and Goda (1982). Table 1 lists the 

 ranges for each of these parameters that was capable of being, but was not 

 necessarily, addressed in each test facility used in this test series. 



15. Reflective properties of a structure relative to incident wave 

 conditions also should have a direct impact on toe berm stability. Unlike 

 Brebner and Donnelly (1962) and Tanimoto, Yagyu and Goda (1982) who examined 

 toe berms fronting highly reflective vertical structures, these tests 

 addressed toe berms fronting less reflective rubble-mound structures. This 

 decrease in reflectivity should lead to differences in berm stone stability 

 from that determined by Brebner and Donnelly (1962) and Tanimoto, Yagyu, and 

 Goda (1982) . 



16. Other parameters that can influence berm armor stability are stone 

 shape k. , unit weight 7 r , gradation and porosity p , stone placement 

 techniques, and angle relative to horizontal (slope) on which the berm stone 

 is placed. For the berm stone designs developed and recommended herein, all 

 these parameters were held constant (i.e., stone with rough angular shape 



(k. = 1.0), unit weight of 165 pcf, berm stone weight gradation of ±30 percent 



of W 50 , and in-place porosity of approximately 37 percent for randomly 



placed berm stone on a flat slope) . If a proposed design deviates greatly 



from these, some difference in berm armor stability response should be 



expected. 



Buttressing stone tests 



17. Using the existing flume calibration, the tribar and toe buttress- 

 ing stone test section was subjected to wave and water level conditions that 

 were very close to the design conditions for the tribar rehabilitation work 

 done on the Hilo Breakwater (Markle (1986) and Sargent, Markle , and Grace 

 (1988)) as well as some additional conditions. A tabulation of tests is 

 presented in Table 2. 



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