The Study On The Earthquake Response Of Parallel Composite Isolation System

The composite isolation system is composed of laminated rubber isolation bearings and friction-sliding isolation bearings according to a certain proportion. In the earthquake, the laminated rubber isolation bearings can extend the structural natural periods and provide reset force. Friction-sliding isolation bearings can provide friction to absorb the earthquake energy. The composite isolation system makes the complementary strengths of two traditional bearings.In this paper ,we firstly carried out the shaking table test of the composite isolation structure model,obtained some useful results, then simulated the test by SAP2000 finite element software. By Setting the software parameters,the software analysis and experimental results are as close as possible. It verifies the correctness of modeling methods and parameter settings of software. And because of the limitations of shaking table tests, we made the model of actual composite isolation structure by applying the same modeling methods and parameters settings.In the establishment of model with SAP2000, in order to consider the impact of structural characteristics to isolation layer, different layer structures were established. In the time-history analysis with the software, we considered the impact of different site classification on isolation layer by different characteristics of seismic waves, researched a reasonable range of the friction pressure by adjusting the arrangement of the isolation layer, analyzed the performance of isolation layer through the observation of composite isolation structure displacement, basal shear ,and concluded reasonable decorate plan of the composite isolation structure which is insensitive to structural characteristics and site classification.With six floors frame structure as an example, we established the traditional anti-seismic structure model, pure rubber isolation structure model and composite base-isolated structure model with SAP2000 , and made the time-history analysis. The analysis indicates that the earthquake response of the isolation layer and the upper structure of composite isolation structure is significantly lower .The composite base-isolated structure has significant effect of seismic resistance and seismic isolation.To sum up, the composite base-isolated structure with reasonable arrangement isolation layer, has good isolation and shock absorption effect, and is not sensitive to the influence of external factors, and has certain advantages compared to pure rubber isolation structure.