Three-dimensional effect of turbulence on the gust-loading and buffeting response of a cable-stayed bridge with projecting-slab box girder

Traditional pressure measurements fail to determine the buffeting force on bridge decks with complex configurations, such as truss or box girders with two slabs. The high-frequency force balance (HFFB) provides an efficient way to solve this aerodynamic issue. This work aims to clarify the spatial distribution characteristics of gust loading acting on a strip of a bridge deck with a projecting slab using force measurements with double-HFFBs. Based on Ribner’s three-dimensional (3D) spectral tensor theory, the relationship between the buffeting forces on an equivalent strip and segment can be derived. The three-dimensional aerodynamic admittance (3D) can be identified considering the 3D effect of turbulence, which can be decoupled into 2D AAF and spanwise correction factor. The results show that the influences of segment lengths and turbulence on the 2D AAF and coherence of the equivalent strip can be eliminated, indicating the validity of the proposed approach. Finally, the applicability of strip theory in estimating the buffeting response of long-span cable-stayed bridges is investigated using finite element analysis.