Dynamic response of a sea-crossing cable-stayed suspension bridge under simultaneous wind and wave loadings induced by a landfall typhoon

Abstract

Sea-crossing bridges with long spans are sensitive to wind and wave environments. The estimation of the dynamic response under simultaneous wind and wave loadings is hence important for the safety of bridges, especially during the landfall of typhoons when extreme wind and wave actions usually occur. In this paper, a framework combining the simulation of typhoon wind and wave fields, calculation of aerodynamic and hydrodynamic loadings, and structural analysis was adopted to assess the dynamic response of a sea-crossing bridge. A cable-stayed suspension bridge located in the typhoon-affected area was taken as an example. The inhomogeneity of wave loading, the time-varying dynamic response of bridges during the landfall process, and the effect of critical wave load calculation on extreme response were presented and discussed. Results demonstrated that wave loadings at different pies show strong inhomogeneity during the landfall process. The typhoon-induced simultaneous wind and wave loadings could affect not only the amplitude of the power spectrum density but also the number of dominant modes of the response. In addition, the error brought by excluding the wave inhomogeneity and the time lag of wind and wave in estimating the extreme response was acceptable when the maximum wind loadings were adopted.