dg changes) . The maximums [R/H^ and R) may occur at any value of dg/H^ 

 (including dg/H^ = 0) depending on the wave steepness being considered. 

 Runup maximums would occur at intermediate values of dg/H^ (1-0 <_ 

 dg/H^ :< 1.5) for high values of H^/gT^, but at low values of d^/H^ 

 for low values of H^/gT^. 



For a given wave period and constant depth, dg (with wave steepness 

 varying as dg/H^ varies), maximum dimensional runup is generally not 

 coincident with maximum relative runup; furthermore, the maximum dimen- 

 sional runup may occur at other than the minimum dg/H^ value. 



The designer of a structure subject to runup will usually have a 

 range of wave conditions for which maximum runup must be determined. The 

 preceding discussion emphasizes the need to determine the maximum actual 

 runup by finding the runup for each of several wave conditions. Example 

 problem 3 (Sec. V) highlights some of the relationships discussed here 

 and shows the maximum runup values for different sets of initial wave 

 conditions. 



IV. SMOOTH-SLOPE SCALE-EFFECT CORRECTION 



The smooth-slope runup curves plotted in Figures 2 to 11 are based 

 on small-scale wave-flume tests. A limited number of large-scale tests 

 (Saville, 1958) indicated scale effects were present in the runup results. 

 Figure 13 presents values of the correction factor, k, as a function 

 of structure slope; the curve is modified from that given in the SPM, and 

 is extended over steeper slopes. 



Selection of a particular structure slope may be dependent on evalua- 

 tion of runup on different slopes. The trends in runup on different 

 structure slopes are presumed correct as given by the design curves 

 (Figs. 2 to 11). Comparisons of runup for different structure slopes 

 should be based on the design curves, with the scale-effect correction 

 applied only to the final selected runup value. 



V. EXAMPLE PROBLEMS 



The following example problem solutions use Tables C-1 or C-2 in the 

 SPM and the applicable curves in this report. 



EXAMPLE PROBLEM i * * * * * 



GIVEN: An impermeable structure has a smooth slope of 1 on 3 and is 

 subjected to a design wave, H = 8 feet (2.4 meters), measured at a 

 gage located in a depth, d = 30 feet (9.1 meters). Design wave 

 period is T = 8 seconds. The structure is fronted by a 1 on 90 

 bottom slope extending seaward of the point of wave measurement. 

 Design depth at structure toe is dg = 25 feet (7.6 meters). (Assume 

 no wave refraction between the wave gage and structure.) 



24 



