LIST OF TABLES 

 No. Page 



1 Comparison of Values of a crit and r) for Use 



in Equation 12 14 



2 Scour Prediction Methods for Various Scour Modes 53 



LIST OF FIGURES 

 No . Page 



1 Forces on a particle in unidirectional flows 8 



2 Curve representing conditions of incipient motion 



in unidirectional uniform flows 11 



3 Komar and Miller (1974) plots of near-bottom orbital 

 velocity for threshold of sediment movement under 



oscillatory waves (extracted from Hales (1980)) 13 



4 Einstein's relationship between $ and V (Herbich 



et al. 1984) 17 



5 Empirical relation for bed- load transport using data of 



Kalkanis and Abou-Seida (after Hales (1980)) 19 



6 Scour problems with rubble-mound structures 23 



7 Scour problems at vertical piles 24 



8 Scour problems at vertical seawalls 26 



9 Scour problems at pipelines 26 



10 Composite cross section proposed by Sawaragi (1966) 30 



11 Stability number cubed versus relative berm 



depth from Markle (1989) 31 



12 Stability number cubed versus relative berm depth for toe berms 

 fronting rubble -mound structures and rubble toes and foundations 



for impermeable vertical structures (after Markle (1989)) .... 32 



13 Maximum scour depth versus deepwater wave height for 



vertical seawalls 37 



14 Definition sketch for Jones' method 38 



15 Predicted scour depths versus measured scour depths using 



proposed equation with irregular wave data only 41 



16 Pipeline scour problem as described by Hennessy and Chao 45 



17 Friction factor versus grain Reynolds number 46 



18 Maximum pipeline scour as a function of bottom 



velocity for d = 0.0082 ft 48 



