with all seaward bar angles for a given shoreward bar angle. A different 

 shoreward bar face was attached to the bar, and waves were generated over the 

 range of seaward angles. Wave height and period were changed to yield a 

 different H /L value after tests were made for all bar configurations, and 

 the procedure was repeated. 

 Pilot test 



112. A pilot test was performed as a trial of the methodology and vali- 

 dation of the criterion on bar depth given by Larson and Kraus (1989) prior to 

 actual testing. In this pilot test, the wave conditions and equilibrium bar 

 formed in a large wave tank test conducted by Saville (1957) was reproduced at 

 the smaller scale of the present study. 



113. Stive (1985) conducted tests in a large and small tank for similar 

 wave steepnesses to make a scale comparison. Stive found that scale effects 

 were not significant for wave height in the range of 0. 15 to 1 . 5 m. A large 

 erosional bar was formed in Saville (1957) test CE400 (Kraus and Larson 1988); 

 therefore, this case was selected to model. The deepwater wave steepness was 

 scaled using the Froude model law (Stevens et al . 1942) in the small-scale 

 experiment; 



(73) 



in which the subscripts pr and m denote prototype and model, respectively. 

 Combining Equations 1 and 73 results in: 



( H o)m = ( H o)j 



(74) 



A wave period was selected as input to Equation 74 that would result in a wave 

 height which could be generated in the tank (h = 1.25 ft) and which would also 

 give a height greater than 0.15 m. The model and prototype test results for 

 Case CE400 are listed in Table 6. Although H /L was slightly higher in the 

 small-scale tests because of differences between the design and measured 

 waves, the bar caused wave breaking and validated the criteria of Larson and 



71 



