Dynamic response of sea-crossing bridge under combined seismic and wave-current action

Offshore structures in earthquake-prone areas are threatened by seismic and wave currents. The dynamic response of a cross-sea bridge with rectangular pier under the action of earthquake and wave is analyzed in this paper. Firstly, the main girder structure and pier structure of the sea-crossing bridge are discretized as Euler beam element and fiber element (nonlinear) by finite element method, respectively. Moreover, the waterstructure interaction is replaced by additional mass, and the soil-structure interaction is replaced by horizontal spring, horizontal damping, rotating spring and rotating damping. After that, based on the analysis of the natural vibration frequency of the structure, the influence of the interaction between the water-structure and the soil-structure stiffness on the natural vibration frequency of the structure is discussed. The effects of structure nonlinearity, soil foundation spring, soil foundation damping, hydrodynamic pressure, travelling wave and wave force on sea-crossing bridge are studied based on dynamic response analysis.