CONTENTS 



F IGURES— Continued 



Page 



10 Two photos of wake region behind 1.5-inch circular pile 



with wave crest incident from top of frame 26 



11 Measured W(a) in same test situation as Figure 10 



26 



12 Photo sequence of wave cycle at 3-inch circular pile, 



with T = 2. 32 -second wave traveling toward the right and 

 one-eighth second between frames 27 



13 Incident, a = 0'', and a = 180° waveforms in same test situation 



as Figure 12 29 



14 Photo sequence of wave crest striking side-by-side circular 



and finned circular piles, with one-eighth second between 

 successive frames 30 



15 Photo sequence of wave crest incident into channel of Sxl 



H-pile, with one-sixteenth second between successive frames. . 32 



16 Photo sequence of wave crest incident on 5x1 H-pile, oriented 



at g = 90°, with one-eighth second between successive frames . 34 



17 Three runup regimes at a shallow-draft obstacle with 



increasing flow velocity, u < u < u 36 



18 "Stairstep" runup in channels around a pile with 25 fins. ... 37 



19 Similar trends in measured runup for various waves at 



circular pile (a = 0°) and H-pile (B = 0°) 39 



20 Normalized peak water patterns at circular pile and 



H-pile in four wave conditions 40 



21 W(a)/W patterns at 3-inch circular pile as W increases. ... 42 



22 [W(ot)/W] patterns at 3-inch circular pile with identical 



incident wave height at three periods 43 



23 [W(a)/W] patterns at 6-inch circular pile as W increases. . . 43 



24 W(a)/W patterns for the same test situation at two length 



scales 46 



25 W(a) for four different crests, and curves fitted by 



symmetric series method 47 



6 



