Analysis Of Seismic Response And Parameters Of Frame Isolated Structure Under Long Period Ground Motion

Since the Wenchuan earthquake and the East Japan earthquake,the engineering circle has paid more and more attention to the earthquake damage caused by long-period earthquake.After the base isolation of high-rise buildings,the period becomes larger and becomes a long periodic structure.It is easy to produce resonance and cause damage under long period ground motion.The study shows that the isolation structure has good isolation effect under short period earthquake,but the seismic response and parameter influence of the isolated structure under long period earthquake are still to be studied.This article launches this question.In this paper,a eight layer isolation structure as the research object,long cycle and short period seismic nonlinear time history analysis,from the structure of the shear layer,interlayer displacement angle,top acceleration,bearing deformation and other aspects of the analysis of difference between different structural response under earthquake.The results show that the seismic responses of the traditional seismic structure and the isolated structure are larger than those under the short period ground motion under the long period ground motion.Bearings also play a good isolation effect on long-period ground motion,horizontal shear,the interlayer displacement angle and top acceleration response has been very good control in isolation,the upper structure is the overall translation,the maximum displacement of isolation structure occurred in the isolation layer.The displacement deformation of the isolation support is 3 to six times larger than that under normal seismic responses.In this paper,a dynamic program is compiled with MATLAB language to obtain the effect of seismic response and the change of the parameters under different types of ground motions on the isolation effect.The results show that the damping ratio of the superstructure is controlled between 0.05-0.1,which can significantly reduce the top acceleration.Under long period ground motion,the damping ratio of isolation layer is larger than that under short period earthquake,and the optimum range is between 0.2-0.33.When choosing the design parameters of seismic isolation,the optimum shock absorption effect can be obtained by considering the characteristics of the site type,the period of the isolation structure,the horizontal stiffness,damping ratio,yield strength and so on.