| Seismic isolation and energy dissipation are two effective measures to control the seismic response of structures.Base-isolated technique means setting an isolation layer between the upper structure and foundation to reduce the seismic responses of upper structure because of large drift of isolation layer.Energy dissipation technique means attaching some energy dissipation devices in the structure,by which earthquake energy consumed to reduce seismic response of main structure.The lead rubber bearing(LRB)is common isolation components.The lead core consumes seismic energy by its plastic deformation.To some extent,the role of the lead and damper is similar.but the lead core has the defect in environmental pollution.In the paper,a new type of seismic isolation bearing was researched,which was composed of natural rubber bearings and damper made of superplastic alloy material(Zn-22%Al).The main contents include: Firstly,the equivalent stiffness and damping of the U-type Zn-22%Al metal damper were analyzed by ABAQUS.Then the seismic isolation effect of buildings with the isolation layer attached this additional damping studied.The author established four structural models through Sap2000: non-isolated structure model;base isolated structure model with common LNR;base isolated structure model with LRB;base isolated model with LNR and U-type damper.The seismic responses of each model due to ground motion were calculated by the time history analysis method.The results showed that:1.The hysteresis curve of U-type Zn-22% Al metal damper was full,so it was a good energy dissipation device.2.Compared with the non-isolated structure,these three kinds of isolation equipment could obviously reduce the seismic responses of the structure.The isolated structure of LNR and additional U-type damper was better in isolated than that of the LNR;3.U-type Zn-22% Al metal damper had significant capacity in energy dissipation,and could play the role of lead core to a certain extent. |
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