Effects and Mechanisms of Railing Height and Inclination Angle on the Vortex-Induced Vibration Performance of a Two-Box Edge Girder

Two-box edge girders are widely employed in bridge engineering owing to their superior mechanical properties. However, these girders are susceptible to vortex-induced vibrations (VIVs) due to their blunt configuration. Therefore, it is of great significance to study their VIV performance and specific suppression measures. Wind tunnel tests simultaneously measuring vibration and pressure and computational fluid dynamics (CFD) were performed to investigate the effects of sidewalk railing height and inclination angle on the VIV responses at different wind attack angles. Furthermore, surface pressure distribution, the relationship between distributed aerodynamic lift and the general vortex-excited force (VEF), and flow field characteristics were analyzed to elucidate the VIV suppression mechanism. Results indicate that vertical VIVs occur across all tested wind attack angles, with the most pronounced response observed at α = +5°. Both railing height and inclination angle significantly influence the VIV response, yet their influence patterns are different. Specifically, the VIV amplitude consistently increases with railing height across all wind attack angles, whereas the effect of the inclination angle varies depending on the wind attack angle. The leading and trailing edges of the upper surface and the trailing edge of the lower surface are identified as the critical areas responsible for VIV. The variations in fluctuating pressure coefficient and contribution value with railing configuration are generally consistent with those of the VIV response. Moreover, while the railing configuration does not alter the vortex shedding mode, it significantly modifies the vortex scale and pressure intensity, thereby resulting in distinct VIV responses.