SOLUTION : These conditions are similar to those tested by Hudson (1959) 

 From Table 22, k & 1.06 for a slope of cot 9 = 1.5; although k is 

 expected to decrease for more gentle slopes, cot 9 = 2 is close to 

 cot 9 = 1.5, and k = 1.06 is used. Therefore, 



o I corrected 



(k) 



(%) 



small scale 



^o ) corrected 



[ n o I small scale 



************************************ 

 ************* EXAMPLE PROBLEM 14 ************* 

 GIVEN : Riprap slope, cot 9 = 3; g = 0; d g /ti^ *4.5; H^/gT 2 » 0.0085. 



FIND : Determine the runup, R, for a structure in a depth of 8 meters 

 (26.2 feet) . 



SOLUTION : Stone size is not given; however, a large value of ti^/k r 



is assumed (e.g., ti^/k r < 4), thus using conditions close to maximum 

 for riprap stability and for which runup may be relatively large 

 because of the large wave to stone size. From Figure 40, for 

 cot 9 = 3 and H*/gT 2 = 0.0085, R/H' * 0.88. 



x d c 



(V» 



= (0.88) x LL-J x 8 



R = 1.56 meters (5.1 feet) 



Scale-effect correction factor, k, is 1.0 because Figure 40 is 

 based on large-scale tests. Thus, R «* 1.56 meters is the full- 

 scale runup. 



VII. RECOMMENDATIONS FOR FUTURE RESEARCH 



In this study, a number of reports have been reviewed which, collec- 

 tively, provide a large amount of valuable data; however, data gaps 

 remain and future research should be directed at filling those gaps. 

 Recommendations for planning and data collection are: 



(a) For each wave period and water depth used, a wide range of 

 wave heights is desirable to discern trends in relative runup for the 

 particular conditions. Incident wave heights would best be measured 

 in the uniform depth part of the wave flume. When testing structures 

 fronted by either horizontal or sloping bottoms, d s /gT 2 should 



119 



