To investigate the seismic response and seismic reduction effects of large-span cable-stayed bridges under different seismic excitations,a three-dimensional finite element model of a sea-crossing bridge was first established based on finite element software,and the structural natural vibration characteristics of the bridge were presented.Secondly,based on the site conditions at the bridge site,various types of ground motions were selected as the ground motions for subsequent dynamic response analysis.Finally,based on the nonlinear time history analysis method,the dynamic response of the structure under various complex seismic actions was studied,and the damping parameters were studied to explore the damper damping scheme of the cable-stayed bridge.Research shows that internal forces of the bridge tower under longitudinal and vertical earthquakes reach maximum,and the maximum shear force and bending moment are 2.46×104kN and 4.53×105kN·m,respectively.The closer it is to the side cable,the greater the axial force and stress of the cable are.The maximum vertical displacement amplitude of the main beam in the mid span under pulse earthquakes is about 0.8m,while the longitudinal displacement of the main beam and tower top is relatively small,with a maximum of about 199.076mm.When the parameters of the liquid viscous damper used at the bridge tower are α=0.3 and C=6000,the optimal shock absorption effect can be achieved.Compared to the state without dampers,the bending moment at the bottom of the tower is reduced by 31.8％～42.7％,the shear force at the bottom of the tower is reduced by 8.8％～13.5％,and the displacement at the top of the tower is reduced by 39.8％～41.9％.
维普
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