PART III: TEST TYPES AND RESULTS 



2-D Toe Berm Stone Tests 



18. Twenty-one tests were conducted. A test consisted of exposing from 

 two to four toe berm plans to a range of wave heights at one wave period and 

 water depth combination. Thirteen tests were conducted using berm armor as 

 specified in Figure 5 as Plan 1 and Plan 2, and eight tests were completed for 

 Plans 5 and 6. Plans 3, 4, and 7 were subjected to five tests each, and 

 Plan 8 was tested for four incident wave and water level conditions. Table 3 

 lists the test conditions, nondimensional parameters, design wave height and 

 toe berm stone stability number N s associated with all tests which showed 

 acceptable toe berm stability (i.e., some stone movement occurred, which 

 showed that the stone was not over designed but the amount of movement was 

 minor and acceptable) . Tests where the toe berm stone either did not move or 

 exhibited excessive (i.e., unacceptable) movement could not be used to 

 formulate design guidance; therefore, these tests are not listed. Stability 

 number is defined as follows: 



\l/3 



W 50 / (S r 



where 



7 r = unit weight of berm stone, pcf 



H D = design wave height, ft 



W 50 = median weight of individual berm stone, lb 



S r = specific gravity of berm stone relative to the water in which the 

 structure is situated, i.e., S r = ~y r /y„ 



7 W = unit weight of water in which structure is situated, pcf 



By cubing both sides and rearranging, Equation 1 takes the following form 



which can be used to directly calculate median berm stone weight: 



7 r (H D ) 3 

 W =>° = N s 3 (S r - l) 3 (2) 



19. Plots of stability number N s versus wave steepness at the toe 



19 



