Structural behavior of a multi-span floating bridge with various taut mooring configurations

Floating bridges are intricate structures that rely on buoyancy for support and utilize mooring lines to provide structural stability, thereby enhancing the ability to withstand various environmental loads. However, in mild fjord conditions, the impact of mooring configurations is often overlooked. This paper presents a numerical study of the dynamic response of a multi-span floating bridge under various mooring schemes. A simplified method for representing hydrodynamic coefficients is first proposed and validated against existing experimental data. Subsequently, a series of parametric studies are conducted to assess the impact of different mooring configurations. The results reveal that the combined system with both vertical and inclined cables offers enhanced adaptability across a broad range of sea conditions. Adjusting the horizontal and vertical angles of the inclined cables in the combined system significantly impacts the bridge's dynamic response under swell wave conditions, reducing the mid-span transverse motion standard deviation by up to 58% across various angles. Furthermore, decreasing the stiffness ratio of the inclined cables to the vertical cables effectively reduces the pontoon's roll induced by sway motion, thereby minimizing the rotation of the main girder.