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-2 -1 



Series D' ° Series E' » Series F' ' Series G' Normal 



Figure 7.4. Probability density function for normalized cover depth C* for Series £)', £', 

 F' and G' 



7.3 Damage Variability 



Figure 7.5 shows O5 as a function of mean damage i'for Series D\ £", F', 

 and G' along with Equation 6. 1 . Series B' is included for comparison. This figure 

 indicates that Equation 6. 1 underpredicts damage variability for the new series in the 

 range S= 1-4. But above and below this range the results are inconclusive. The greater 

 variability in damage for the wider gradation (Series F' and G") is expected; but the 

 reason for the greater damage variability for shorter wave periods is not clear. It appears 

 there are insufficient data to make a definitive modification to Equation 6.1. Even 

 though the data are shghtly underpredicted by Equation 6.1, Equations 5.10 and 6.1 



133 



