An Advanced Approach to Determining the Spanwise Coherence of the Buffeting Forces on Bridge Decks with Complex Configurations

Abstract

The spanwise coherence of aerodynamic forces on a strip section is vital to evaluate the buffeting response of large-span bridges. However, when employing the commonly used pressure measurement technique, it is difficult to obtain the buffeting force coherence of bridge decks with complex configurations. This paper aims to propose an approach to determining the buffeting force coherence of a strip section using the force measurement technique. The key to this approach is the transformation of the coherence of buffeting forces from segment models to strip sections. Based on the two-wavenumber buffeting analysis theory, the relationship between the coherence of a strip section and a segment model is elaborated theoretically. The influences of the aspect ratio (δ) and the ratio of the integral scale to half the model’s width (Lw/b) on buffeting lift coherence were investigated. Force and pressure measurement tests are conducted on a typical streamlined bridge deck to validate the proposed approach. The results show that the buffeting lift coherence of a segment model is much stronger than that on a strip section. An increase in δ or Lw/b can, respectively, enhance the buffeting lift coherence at low wavenumbers or high wavenumbers. The wind tunnel test results demonstrate that the proposed approach is feasible and reliable and can be easily utilized to identify the buffeting force coherence of a bridge deck with a complex configuration.