Numerical modeling of current-induced scour around multi-wall foundation using large-eddy simulation

Scouring is one of the primary triggers of failure for bridges across rivers or seas.However,research concerning the scour mechanism of multi-wall foundations(MWFs)remains scarce,hindering the further application of MWFs.In this study,for the first time,the scouring effect caused by unidirectional flow around MWFs was examined numerically using FLOW-3D involving a large-eddy simulation.Initially,the applicability of the scouring model and input parameters was validated using a case study based on published measured data.Subsequently,the scouring effects of four MWFs with different wall arrangements and inflow angles,including the flow field analysis and scour pit and depth,were investigated thoroughly.It was found that the maximum scour depth of MWFs with an inflow angle of 0°was smaller than that of those with an inflow angle of 45°,regardless of the wall arrangement.Meanwhile,changing the inflow angle significantly affects the scour characteristics of MWFs arranged in parallel.In practical engineering,MWFs arranged in parallel are preferred considering the need for scouring resistance.However,a comparative analysis should be performed to consider comprehensively whether to adopt the form of a round wall arrangement when the inflow angle is not 0°or the inflow direction is changeable.