structure fronted by a 1 on 10 bottom slope; the structures in other 

 tests extended to the flat bottom of the wave tanks. 



Saville's results for the 1 on 1.5 stepped slope are plotted in 

 Figures 45 and 46. Figure 45 has the data points for a depth greater 

 than zero at the structure toe. Figure 46 has data for a zero toe 

 depth at the structure; however, slightly different dimensionless 

 variables are used. Both on the stepped slope and on smooth slopes 

 the relative depth, defined at some point seaward of the structure, is 

 important even with a zero toe depth. Curves of constant dg/H^ have 

 been drawn in Figure 45. The ratios of stepped-slope runup to smooth- 

 slope runup are given in Table 16 for water depths greater than zero at 

 the structure toe, and in Table 17 for the zero water depth. The r 

 value for d s /H£ = 0.38 in Table 16 is based on one point only and a 

 higher average value would be expected. 



Table 16. Ratios of stepped-slope runup to smooth-slope 



runup; 1 on 1.5 structure slope; 1 on 10 bottom 

 slope; d s > (after Saville, 1955). 



da/ H o 



H^/k r 1 



r (avg) 



0.38 



12.0 



0.56 2 



0.75 



6.0 and 12.0 



0.74 



1.5 



3.0 and 6.0 



0.80 



3.0 



3.0 



0.76 



l k r is the step height. 

 2 Based on only one point, 



Table 17. Ratios of stepped-slope runup to smooth-slope 



runup; 1 on 1.5 structure slope; 1 on 10 bottom 

 slope; d s = (after Saville, 1955). 



d/HJ l 



H^/k r 2 



r (avg) 



4.1 

 8.3 



6.0 



3.0 



0.70 

 0.74 



x Use d/H^, not d s /H^ 

 2 k r is step height 



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