To address the challenges of numerous piles and columns,complex modeling,and lengthy computation times in actual wharf engineering projects,we innovatively employ three-dimensional sediment transport model to investigate the local scour characteristics of typical pile-column groups under different arrangements,reveal the scour depth,extent,and local velocity changes within pile-column clusters,and verify by single-column local scour results.The simulations of different pile-column configurations demonstrate distinct differences in scour depth and morphology among single column,double columns,and pile-column groups.As the number of pile-columns increases,local scour depth gradually decreases while scour patterns become more uniform.Under high flood conditions,significant local scouring (3.30-4.31 m) occurs at the pier columns of the wharf approach bridge (twin columns aligned with the flow),particularly pronounced in the inter-column zones.The scour around the wharf platform piles (a typical pile cluster) is relatively uniform (2.5-4.0 m),though high-velocity zones may intensify scouring.The typical three-pile cluster exhibited shallower scour,effectively reducing the scour depth of the main piles.Rational placement of fender piles can significantly reduce both the scour extent and depth.The findings on local flow velocities,scour depth,and extent under high flood conditions provide a basis for determining design parameters such as rock size and protection range for pile column protection in the middle and lower reaches of the Yangtze River.