Simplified analysis method for pontoon-supported floating bridges under waves

In this study, a simplified analysis method was proposed that can be used in the conceptual design phase of floating bridges. The proposed method involves a coupled dynamic analysis based on commercial structural analysis software without the implementation of a convolutional integral for the continuously retarded hydrodynamic damping term within the equation of motion. Instead, the method uses equivalent constants to account for damping and additional underwater inertial effects. The target model was a straight pontoon-supported floating bridge with a length of 4.6 km, considered for the Bjørnafjord on the west coast of Norway. This paper presents a reasonable modeling approach for the hydrostatic and hydrodynamic components of a floating bridge and the application of wave loads based on pre-evaluated wave load transfer functions. The effectiveness of the proposed method was validated by comparing the analysis results for the behavior of a floating bridge under wave conditions with the results of OrcaFlex. The behavior of the floating bridge was investigated under various wave conditions, demonstrating an acceptable level of error in the overall response of the bridge girder.