would take these structural distortions into account is currently being 

 investigated. The reader should also note that the impact response will be 

 correlated with the hydro dynamic stability. Therefore, the impact response 

 will be a function of the same variables as is the hydraulic stability. These 

 variables include wave direction, wave length, wave shape, structure slope, 

 spectral width, etc. What is left after detrending, demeaning, and despiking 

 the time series is the pulsating response. 



87. Many tests are required in order to determine a statistically 

 representative sample of the maximum stresses in the armor layer. The number 

 of these tests can be reduced by utilizing results of recent parametric 

 studies. The maximum static stresses will be in the underlayer. To test for 

 static stress, several instrumented dolosse can be placed on a small ramp at 

 the prototype slope and density, along with many noninstrumented dolosse. The 

 static response can then be measured for both the nested and unnested 

 conditions. The nested configuration can be achieved by shaking the ramp. 

 Scaling factors for wedging loads, size, and material density can be applied 

 to these data to determine the maximum static stress distribution. 



88. Recent studies indicate that the pulsating stresses are maximum 

 above and near the still-water level. Pulsating and impact structural 

 measurements can therefore be limited to two to three dolosse placed at and 

 near the still-water level. Also, for pulsating and impact responses, no 

 additional wave conditions beyond those used to test hydrodynamic stability 

 need be run. The individual nondimensional design EPFs for the static, 

 pulsating, and impact responses will be generated from the model data in this 

 intermediate design phase. Techniques for fitting the best distribution to 

 the data are described in Burcharth (1985) and include choosing a distribu- 

 tion, comparing plotting rules, noting variations and uncertainties, and 

 quantifying distribution errors. 



89. Proper attention to scaling is required in order for the results 

 of the small-scale structural measurements to be meaningful. Scott, Turcke, 

 and Baird (1990) and more recently, Anglin et al . (1990) have reported the 

 results of a large series of parametric physical model tests using small-scale 

 model dolosse. The results show static stresses, when scaled to the prototype 

 level, far below those measured in the Crescent City prototype dolosse. This 

 difference may be attributed to the improper scaling of static wedging loads 

 in the small-scale units. Melby, Rosson, and Tedesco (1990) compared Crescent 



39 



