is desired, the runup produced by a larger design wave can be estimated 

 after considering the water level produced by wave setup (using Hg) and 

 other effects (e.g., astronomical tide, wind setup). Tlie selection of a 

 design wave for runup considerations is left to the designer based upon 

 the requirements of the project. 



The setup estimates using the methods described in this report are 

 based upon the assumption that the waves approach normal to the coast. 

 A wave that approaches the coast at an angle has components normal and 

 parallel to the coast. The normal component produces wave setup, the 

 parallel component produces a longshore current. It is reasonable to 

 assume that the setup is a function of the cosine of the angle between 

 the wave crest at breaking and the shore. Reducing the estimated wave 

 setup in this manner is left to the judgment of the designer. 



III. SAMPLE DESIGN PROBLEMS 



The following examples show the use of the techniques presented in 

 the solution of typical design situations. Refer to the SPM for other ' 

 information related to the total design problem (e.g., wave theory, 

 refraction analysis, tides, storm surges, wave breaking). 



************** FXAMPLH PROBLEM 1************** 



GIVEN : A wave gage is located in 22 feet of water at MLW (see Fig. 4). 

 Analysis of the gage record for a period during a storm yields a sig- 

 nificant wave height, Hg = 20 feet and period, Tg = 12 seconds. Assume 

 the direction of wave approach is normal to a straight coast with 

 parallel contours (i.e., refraction coefficient = 1.0), 



FIND : The maximum water level at the beach where runup calculations 

 can be made considering an initial SWL at MLW. 



SOLUTION : From the given conditions in Figure 4, the significant wave 

 will break offshore of the shelf and induce a setup. First, define the 

 unrefracted deepwater wave height, H^, and the breaker height, H^. 

 Using the methods given in SPM (App. C, Table C-1), the following wave 

 height values were obtained for 



d 22 



= 0.02984 



Lo 5.12(12)- 



H 



— = 1.126 



K^ = 17.76 feet 

 by referring to Figure 2 with m = 0.05, and 



14 



