Effects of inhomogeneous wave modeling on extreme responses of a very long floating bridge

Floating bridges are usually deployed in fjords where the wave fields are inhomogeneous. The wave in -homogeneity has been found to induce significant effects on dynamic responses, however, it was rarely considered during the extreme response analyses of floating bridges. The present study deals with the effects of inhomogeneous wave modeling on extreme responses of a very long end-anchored floating bridge. The inho-mogeneous wave field modeling accounts for the spatial variation of wave spectral parameters as well as the coherence of wave elevations between different positions. Structural responses under various wave conditions are simulated through fully-coupled hydro-elastic simulations. The long-term extreme responses are investigated by a simplified environmental contour method, where the long-term extremes are approximated by extremes at a high quantile in carefully selected short-term sea states. The characteristics of simulated waves and responses are first analyzed to serve as a basis for extreme prediction. Uncertainties associated with extreme analyses are also studied. It is found that the coherence of wave elevations has significant influences on the standard deviation and the spatial correlation of the responses. The extreme values of the axial force vary between different modeling of inhomogeneous wave loads and become significantly larger considering partially correlated wave fields.

Automated summary

This study investigates the effects of inhomogeneous wave modeling on the extreme responses of a long end-anchored floating bridge. The inhomogeneous wave field modeling accounts for the spatial variation of wave spectral parameters and the coherence of wave elevations between different positions. Structural responses under various wave conditions are simulated, and long-term extreme responses are approximated using a simplified environmental contour method. The study finds that the coherence of wave elevations has a significant influence on the standard deviation and spatial correlation of the responses, and extreme values of the axial force vary between different inhomogeneous wave load models, especially considering partially correlated wave fields.