Seismic Safety Performance Design Method And Vulnerability Analysis Of Seismic Isolation Structure

With the development of science and technology,foundation isolation has become a safe and efficient building seismic mitigation technology.Foundation isolation technology can be used not only for the seismic design of new projects,but also for the seismic strengthening of existing buildings,and its excellent seismic performance has been confirmed by many shaking table experiments and theoretical studies.Therefore,an in-depth discussion of the seismic response of seismically isolated structures will provide an extremely important reference basis for ensuring the safety of public life and property.The detailed design of seismically isolated structures is more mature,but the design process usually does not analyze the performance states and indicators of seismically isolated structures when they are exposed to earthquakes.In addition,the risk and damage assessment of the seismically isolated structures after encountering an earthquake is also an aspect worthy of study.Therefore,this study investigates the evaluation of seismic safety performance of seismically isolated structures from the beginning of design and in the future when they encounter different earthquake intensities.Firstly,the basic principles of seismic isolation technology are introduced,and the mechanical model of the foundation seismic isolation system and its dynamic equilibrium equation sources and solutions are summarized,and the performance parameters and mechanical model of the seismic isolation bearings are briefly described.Secondly,Pushover analysis of the seismic isolation structure is carried out,and the lateral load loading mode suitable for the seismic isolation structure and the loading control mode suitable for the torsional irregular structure are studied.The seismic performance of the isolated structure is evaluated by using the capability spectrum method suitable for the isolated structure.The practical design method of the seismic isolation structure based on Pushover is proposed.The performance requirements of the superstructure are determined by the Pushover method,the design objectives for the seismic isolation layer are determined according to the superstructure property level,the parameters and arrangement of the seismic isolation bearings are determined by these indicators,and the overall seismic performance of the design is evaluated by applying the Pushover analysis method to ensure the seismic performance of the seismic isolation structure.performance index.The incremental dynamic analysis of the seismic isolation structure is carried out by using the inter-story displacement angle and the seismic isolation layer displacement as performance indexes,and the seismic susceptibility analysis method is introduced to carry out seismic susceptibility analysis of the seismic isolation structure and draw seismic susceptibility curves to evaluate the seismic safety performance of the base isolation structure.For the torsional eccentric structure,the inter-story displacement angle and inter-story torsion angle are used as performance indexes to analyze the susceptibility of torsional irregular structure and evaluate the safety performance of torsional irregular structure,and analyze the anti-torsional effect of seismic isolation bearing through the arrangement of seismic isolation bearing.The establishment of seismic susceptibility curves of seismically isolated structures can provide support for seismic risk and loss assessment,seismic mitigation plan,post-earthquake strengthening,determination of maintenance priority level,and seismic optimization design of the structures.