It will be convenient to refer to damage in terms of the nominal stone 

 diameter, so the packing density equation can be rearranged to be compatible as 



K d. 



T = ^ (4-2) 



where (j) is the packing density coefficient. The stone armor layer was placed in a 

 traditional two-layer thickness at an average packing density coefficient of 4) = 1-2, 

 corresponding ton = 2,k^= 1.0, and Pa= 40 percent as recommended in the SPM. 



The core was placed by shovel, troweled to grade, and washed in place to 

 naturally pack tight. This process simulates the natural washing action of waves during 

 the construction sequence. Similarly, the underlayer was dumped onto the sloping core 

 and lightly troweled to grade. Each armor stone was placed individually by hand, 

 simulating crane placement as closely as possible. The armor stone placement during 

 the experiment followed WES guidelines for random hand placement in the laboratory 

 as follows: 



a. Stones were lowered vertically into position. 



b. Stones were placed on the slope rather than dropped. 



c. Stones were placed so that they touched their neighbors. 



d. Stones could not be pushed into a hole. 



e. Particular orientation of stones or placement patterns were avoided. 



59 



