nearshore region, then it may be that the surplus of sand observed in the model surf zone was a result of 

 the offshore sediment requirement having been met. If this is true, it follows that exact reproduction in the 

 model will require correct development of the bar feature and sediment volume in the bar. Several of the 

 additional tests in this model series were designed to investigate this possibility, and they are discussed in 

 later sections of this report. 



103. A second contributing factor to the nearshore model results may have been the aforementioned 

 difference in maximum runup between model and prototype. Greater wave runup should contribute to the 

 corresponding downwash on the face of the revetment, which in turn influences the amount of scouring that 

 occurs at the interface of the structure and sediment. However, this factor is thought to be less important 

 than the equilibrium state of the offshore bar. 



Test with Increased Wave Height 



104. Test T04 was the first of several tests conducted to investigate the relative influences of selected 

 model parameters on the model scaling. In test T04, the wave height in the model was increased by 

 approximately 10 percent over the scaled equivalent of the prototype wave height that was used in test T03. 



Test T04 Results 



105. Test T04 was also conducted in the same manner as the prototype-scale regular wave test. 

 Figure 11 illustrates the temporal development of the profile in the model. Comparisons in Figure 11 are to 

 earlier profiles in this same model test. Wave data and statistics for this test are given in Table B4 

 (Appendix B), profile data are given in Table C4 (Appendix C), and a complete set of profiles for this test 

 is given in Figure D4 in Appendix D. 



106. Similar to test T03, test T04 also exhibited a cross-tank profile variation as the test approached 

 equilibrium cis shown by the profiles in Appendix D (Figure D4). Increased wave heights apparently made 

 the cross-tank variation a little more severe than observed in test T03. Figure 12 shows the average model 

 profile at 1,650 waves compared with the center-line profile. 



42 



