ABSTRACT
Scour by waves around piles as bridge pier’s foundation near shore may cause potential vulnerability of the bridge structure. Wave induced scour around piles is a complex issue which varies with three dimensions in spatial and time. Scour around two piles arranged side by side and a monopile on a sloped beach with a series of solitary waves was investigated based on numerical simulations. An URANS-VOF model coupling with a morphological model and sediment transport models was used to simulate the wave propagations, hydrodynamics, as well as the beach scour around the piles. Nested grids and dynamic grids were used in the zone closer to the piles to capture the local water-sediment interface associated with morphological change or scour.
Through the numerical investigations, following results were obtained: scouring around piles at sloped beach develops twice times faster at the wave running down the slope than that at the wave running up; the maximum scour depth distributes at the side of pile or piles; the first wave contributes over 60 percent to the total scour depth; scour depth decreases with pile spacing increase, and the maximum scour depth locates at front of the two piles.
