Sensitivity analysis of numerical modeling approaches for curved floating bridge buffeting response

Floating bridges provide a feasible and economical solution for spanning vast and deep waterways. Wind-induced response analysis of such structures has received considerable attention in recent years. This study numerically investigates the buffeting response of a 5.5 km curved floating bridge with a supplementary side-mooring system, where skew wind effects are relevant. A finite element model of the floating bridge was developed in OrcaFlex and subjected to wind loads via Python external functions. The study systematically evaluates the effects of various numerical modeling approaches and parameters on the bridge’s buffeting response. Results show that the vertical and rotational responses, which are primarily due to vertical turbulence, are more sensitive to the choice of wind velocity interpolation schemes than the selection of wind field generation tools, such as TurbSim and WindSim4D . Significant differences are observed between the simulated bridge responses when using the nearest-neighbor approximation and the linear interpolation methods for wind velocities. Regarding the wind load modeling in the presence of skew winds, the simplified cosine rule and the 2D (+1D) load formulations tend to underestimate the maximum vertical response compared to the 3D model. Wind evolution in the along-wind direction and the modeling of the uw co-spectrum have marginal effects on the bridge response. In the 3D formulation, the horizontal, vertical, and rotational responses are, as expected, primarily driven by the forces represented by the aerodynamic coefficients C y , C z , and C r x in the local structure-oriented coordinate system. The effect of the translational and rotational self-excited forces on reducing the overall response at the design wind speed is notable for the cable-stayed section of the bridge but limited for the floating bridge part due to the involved hydrodynamic damping. The findings underscore the importance of incorporating improved wind modeling techniques in buffeting analysis for floating bridges, particularly under skew wind conditions. • Investigated buffeting response of curved floating bridges supported by pontoons and mooring lines. • Developed an improved analysis framework incorporating skew winds and hydrodynamic effects. • Evaluated the impact of different wind field generators and wind velocity interpolation schemes. • Analyzed the effects of wind evolution, self-excited forces, and aerodynamic coefficients.