Modeling Free Surface Elevation around Tandem Piers of the Longitudinal Bridge by Computational Fluid Dynamics

Abstract

Abstract This study explores the impacts of tandem piers of longitudinal bridges on the free surface elevation of river flow by computational fluid dynamics(CFD). Water flow around a single pier is simulated to develop the Kármán vortex street model, which also verifies the effectiveness of CFD simulations in this study. Then, the influence mechanism of span on the free surface elevation was analyzed in the light of the streamline of flow at y=0.4m in different times. If the span is shorter than 20D, including20D, the superposition of Kármán Vortex Streets obviously affect the fluctuation of streamline. The leap height of the first pier of different models is very close. If the span is shorter than 40D, the leap height decreases by degrees and finally reaches stability. When the span is greater than 40D, the leap height from the 2nd pier to the last one is close.