Research On The Characteristics Response Of Isolated Structures With Different Dynamic Characteristics Under Near-fault Pulse Type Earthquake

The near-fault velocity pulse type ground motion has a serious damage to the building structure.In the design of building structures,it is necessary to fully consider the dynamic response of structures under near-fault ground motions.This paper analysis the influence on different isolated structures simplified model of near-fault velocity pulse ground motion.The paper improve the design of the isolated structures,which can reduce the response of the isolated structure under the near-fault ground motion.The main research results are as follows:1.Combined with the characteristics of near-fault velocity pulse type,qualitative identification and quantitative identification methods were used to screen out the nearfault velocity pulse ground motion with forward directivity effect and fling-step effect.2.Stacking natural seismic wave and velocity pulse model to manufacture numbers of near-fault velocity pulse ground motions,which enhanced the effect of constructing different velocity pulse ground motion on isolated structures.3.By fixing the limitation,the continuous simplified model of different base isolated structures is realized in the finite element software,which can effectively simulate the dynamic characteristics of the isolated structure under seismic action.4.Based on 42 simplified model of seismic isolation with different structure types,the paper analyzes the effect of the near-fault velocity pulse ground motion with forward directivity effect and fling-step effect.The results show that the velocity pulse ground motion with fling-step effect has great influence on the isolation structure.5.By researching the simplified model of isolation structure with nonlinear bearings and linear damping bearing with different damping ratio,the paper put forward the improvement method to reduce the speed of pulse type isolated structure in the seismic response of the structure,and verify the correctness of the theory by analyzing the actual structure.The results show the effectively reducing of the influence of velocity pulse ground motion on the structure on the combination of nonlinear isolation bearing and linear damping bearing which ratio is 0.1.