H' 1.9 



o 



= 1.58 



Interpolating between Figures 7-10 and 7-11, for a 1 on 2.5 slope, produces 



d 



Figure 7-10: 



-j^ = 0.80 ; |t = 2.80 

 o o 



S R 



Interpolated Value: rrj = 1.58 ; — ^ « 2.5 



o o 



Figure 7-11 



:p= 2.0 ; |^= 2.35 

 o o 



The runup, uncorrected for scale effects, is 



R = 2.5 (Hp 



R = 2.5 (1.9) = 4.8 m (15.7 ft) 



The scale correction factor k can be found from Figure 7-13. The slope in 

 terms of m = tan is 



tan = 



2.5 



= 0.40 



The corresponding correction factor for a wave height H' = 1.9 m (6.2 ft) 

 is 



k = 1.169 



Therefore, the corrected runup is 



R = 1.169 (4.8) = 5.6 m (18.4 ft) 



(b) Riprap on a slope decreases the maximum runup. Hydraulic model studies 

 for the range of possible slopes have not been conducted; however, Figure 7- 

 15 can be used with Figures 7-10 and 7-11 to estimate the percent reduction 

 of runup resulting from adding riprap to a 1 on 1.5 slope and to apply that 

 reduction to structures with different slopes. From an analysis similar to 

 the above, the runup, uncorrected for scale effects , on a 1 on 1.5 smooth, 

 impermeable slope is 



R 



= 3.04 



smooth 



From Figure 7-15 (riprap), entering with H'/gT = 0.0030 and using the 



curve for d /H' = 1.50 which is closest to the actual value of 

 s o 



7-34 



