Abstract
As the span of long-span concrete-filled steel tube (CFST) truss arch bridges continues to increase, their sensitivity to wind significantly enhances, making the study of arch rib stability under wind loads increasingly important. However, current standards for aerodynamic parameters of CFST truss arch bridges are still incomplete, only providing calculated values for the drag coefficients of local bridge components. This study utilizes Computational Fluid Dynamics (CFD) as the primary research tool, combined with existing wind tunnel tests of arch rib segments, to propose a two-dimensional simplified model of a CFST truss arch rib and validate its effectiveness in computing aerodynamic parameters. Based on this model, parametric studies were conducted on the aspect ratio of a single arch rib section and the aerodynamic interference effects between double arch ribs. The research findings indicate that for long-span CFST truss arch rib sections, the empirical formula values specified in the standards are unsafely low. The overall drag coefficient of the arch rib segment shows a trend of initially increasing and then decreasing with the aspect ratio (H/B), peaking at an H/B of 1.5 before continuously declining. It is recommended that the design value for the arch rib H/B be between 1.75 and 2.5. Additionally, once the spacing ratio (L/B) between double arch ribs exceeds 2, the overall drag coefficient of the arch ribs no longer changes with increased spacing. For long-span CFST truss arch bridges, the wind load on the downstream arch ribs can be considered using a shielding coefficient of 0.53 from the upstream arch ribs.
Published Version
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