Research on Seismic Isolation and Seismic Reduction of High-Rise Buildings Bases in High Intensity Area

The seismic isolation effect of different isolation schemes for high-rise buildings in high-intensity area were compared and analyzed, including single lead rubber bearing isolation, single natural rubber bearing isolation, lead rubber and natural rubber bearing mixed isolation, and the above schemes were combined with viscous dampers. Based on the optimal damping indexes and damping coefficients obtained from the analysis, the influence of reducing natural vibration period of non-isolated structure on the seismic isolation effect was analyzed by using the mixed damping scheme of viscous damper and natural rubber bearing. The analysis showed that adding viscous damper in the isolation layer could significantly improve the seismic isolation effect, reduce the horizontal damping coefficient, and reduce the tensile stress and displacement of the bearing. For high-rise isolated buildings with flexible superstructures, it might be difficult to achieve the expected damping target only by adjusting the layout or parameters of rubber bearings and viscous dampers. The more effective method should be improving the stiffness of superstructure and reducing the natural vibration period of superstructure. Increasing damper output could not necessarily reduce horizontal damping coefficient and bearing tensile stress. The damping coefficient and damping index had an optimal value for the influence of horizontal damping coefficient and bearing tensile stress.