TOTAL BERM ARMOR STONE MOVEMENT VS H/HD 



2-D TESTS; 5- & 6.75-FT WAVE FLUMES 



0.6 0.8 1 1.2 



RELATIVE WAVE HEIGHT, H/HD 



1.6 



Figure 20. Total percentage of berm armor stone showing any 

 type of movement (rocking or displacement) versus relative 

 wave height (2-D tests) 



exceeds the design wave height by 30 percent (H/H D = 1.3). For H/H D =1.3, 

 total berm armor movement (Figure 20) could be as high as 26 percent. This is 

 an increase of 18 percent in possible damage over the maximum value of 8 

 percent associated with H/H D = 1.0. 



38. The stability numbers recommended herein for toe berms are for use 

 when designing for breaking waves. For toe berms being designed for nonbreak- 

 ing waves, the SPM (1984) recommends that the toe berm armor stone weight W 50 

 be no less than one tenth the weight of the primary armor stone that would be 

 needed for acceptable stability. It is recommended that this guidance 

 continue to be followed; and for critical structures, the design adequacy 

 should be checked through site-specific model tests. 



34 



