Effects of hybrid seismic isolation device on seismic response of long-span cable-stayed bridge

A long-span cable-stayed bridge with a span(67+110+360+110+67)m is selected to study the effect of hybrid seismic isolation device on the shock absorption limit. The spatial dynamic model was established by finite element software ANSYS, and the effects of hybrid seismic isolation device with friction pendulum bearing and fluid viscous damper on the seismic response of the bridge structure were studied based on the nonlinear time history analysis method. Then, the parameters of the isolation device were obtained by parameter analysis. The research results show that it is possible to resolve the seismic problem of long-span cable-stayed bridge by arranging hybrid seismic isolation device in the longitudinal direction of the main bridge. In comparison to use fluid viscous damper alone, the hybrid seismic isolation device further reduces the internal forces of pylons and transition piers and further reduces the displacements of pylon and girder. Considering the seismic response of the structure, hybrid seismic isolation device of the bridge with the damping index of 0.4 and the damping coefficient of 12 000 kN/(m•s-1)0.4 can achieve a better shock absorption effect. Besides, friction pendulum bearing and fluid viscous damper in hybrid seismic isolation device can work together and achieve significant effect of energy absorption. © 2020, Jilin University Press. All right reserved.