PART III: CONCLUSION 



13. Table 10 summarizes dissimilar armor usage by location, armor type 

 and weight, placement date, and primary basis for armor selection. These data 

 show that in all cases selection of the dissimilar armor type and weight was 

 based on design guidance for new construction, prototype experience, engi- 

 neering judgment, inferences from model tests of similar structures, or 

 site-specific model tests rather than guidance specific to evaluating the 

 interfacing and stability response of the dissimilar armor. 



14. It is reasonable to conclude that the guidance needed for use of 

 dissimilar armor will become more critical in future years as the cost of re- 

 pairs increases and as rehabilitation of major breakwaters and jetties becomes 

 necessary to extend their project life. Table 10 shows that almost half of 

 the existing or proposed dissimilar armor applications have been implemented 

 since 1980. The vast majority of existing Corps structures originally used 

 stone armor; therefore, development of guidance for overlaying large existing 

 armor stone with hydraulically superior units such as dolos and tribars is of 

 great importance if we are to produce effective and economical rehabilitations 

 and repairs. Further, the effects of mixing existing man-made armor should be 

 Investigated to assure major mistakes are not made and to produce new and 

 efficient alternatives to conventional repairs. 



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