Design and Application of Combined Seismic Isolation Device in Double-Pylon Cable-Stayed Bridge

In order to study the isolation effect of combined isolation devices in double-pylon cable-stayed bridge, the Yueqing Bay double-pylon cable-stayed bridge was taken as an example for analysis. The software Midas/Civil was used to build up the spatial finite element model for bridge and the seismic isolation effect of double-pylon cable-stayed bridge is analyzed and compared when only lead rubber bearings and combined isolation devices were used. The results of analysis indicated that the combined seismic isolation scheme with seismic isolation devices installed on bridge pylons and transition piers could achieve better seismic isolation effect. Only using lead rubber isolation bearing could effectively reduce the bending moment at the bottom of the transition pier. Using the combined isolation device scheme could make the capacity redundant components bear part of the seismic force, and the effect was remarkable in limiting displacement and controlling seismic force.The combined isolation device could distribute the force of the bridge better for the sake of achieving the optimal seismic mitigation.