Performance study of viscous dampers in high and low cable-stayed bridges under non-uniform excitation

To investigate the influence of viscous dampers on the seismic response and seismic mitigation effects of high and low tower cable-stayed bridges under spatial effect seismic motions, this study takes the Poyang Lake Bridge as the research object. Using the finite element analysis software Midas Civil, a dynamic analysis model of the entire bridge was established, and non-uniform seismic excitation was applied using the large mass method. By comparing the seismic response of the high and low cable-stayed bridge under non-uniform excitation with different viscous damper parameters, this study explores the seismic response and seismic mitigation effects of high and low tower cable-stayed bridges under various spatial effect seismic motions when viscous dampers are employed. The results indicate: In the consideration of coherent effect ground vibration, the consideration of coherent effect and site effect ground vibration and the comprehensive consideration of coherent effect, site effect and traveling wave effect ground vibration, the viscous damper can be set to equalize the distribution of internal force of the bridge, and when the damping index is 0.3, the damping coefficient is in the range of 4,000 kN/(m/s)a-6,000 kN/(m/s)a viscous damper can effectively control the seismic response of the bridge.