0.15-1.50 ft/sec 



(29) 



which is reasonably consistent with the PIANC criterion in Equation 20 (though 

 the threshold velocity for damage at the shorter periods is much lower than the 

 PIANC values). 



Seabergh and Thomas' 

 criteria (No. 2) can be 

 compared directly with 

 Wilson's criterion (No. 1) 

 (Table 18). Slope values at 

 the high end of the range 

 defined by Seabergh and 

 Thomas' criteria are 

 reasonably comparable to 

 Wilson's criterion. 



In conclusion, the four 

 criteria are reasonably 

 consistent. Considering the 

 major simplifications in the 

 overall problem (partic- 

 ularly the lack of explicit 

 consideration of the type of 

 vessel and mooring system), 

 differences between criteria seem relatively minor. 



Adaptation of HARBD output for comparing harbor plans to operational 

 criteria. None of the criteria seems ideally suited to the physical problem and 

 HARBD's capabilities, but HARBD output can be adapted to give quantitative 

 insight relative to the criteria. More importantly, the criteria provide a conve- 

 nient yardstick for comparing operational performance of alternative plans to the 

 existing harbor. Thus operational experience at existing piers can be applied to 

 piers in the alternative plans. The Wilson and Seabergh and Thomas criteria 

 (Nos. 1 and 2) were used in this study because they are best suited to the 

 standard HARBD output. 



Table 18 



Slope 1 Values Defined By Seabergh 



and Thomas' (1995) Long Wave 



Criteria 



(cm) 



Wave Period, T(sec) 



41 



205 



1,024 



5 



0.0040 



0.0008 





10 





0.0016 



0.0003 



1 Slope values are defined as H SJa ^T, in ft/sec for 

 comparison with Wilson's criterion of HT<0.0038 ft/sec 



68 



Chapter 4 Numerical Model 



