Evaluation Of Seismic Vulnerability And Economic Losses Of Reinforced Concrete Frame Isolation Structures

With the development of isolation technology,the design of isolation structures is becoming increasingly mature.This also allows designers and owners to choose non-isolated structure design or isolation structure design when designing middle and low story reinforced concrete frame structures.Designers need to comprehensively evaluate the seismic performance and economic losses of these two schemes,and provide a comprehensive evaluation index to provide decision-making basis for owners.This article mainly studies the application of isolation technology in RC frame structures in high intensity areas(8 degree areas 0.2g).Conducting time history analysis of isolated and non-isolated structures under frequent and rare earthquakes,comparing the seismic performance and seismic risk of structures before and after isolation,and evaluates the economic losses of structures under earthquake action.This provides a comprehensive evaluation index for the selection of seismic design schemes for RC frame structures.This paper focuses on the following aspects:(1)The seismic performance of an RC frame structure example is analyzed by response spectrum,and the results indicate that the maximum interlayer displacement angle of the structure under frequent earthquakes do not meet the latest code requirements.Therefore,isolation design is carried out for the frame structure.(2)ETABS is used to design seismic isolation structures,and compare it with PKPM modeling after modeling to verify the correctness of the model.Performing time history analysis on non-isolated and isolated structures under frequent and rare earthquakes,using interlayer shear force,interlayer displacement angle,and vertex acceleration as seismic performance indicators.Comparing the seismic performance of structures before and after isolation,and the analysis results show that under the same seismic action,the reduction rates of interlayer shear force,interlayer displacement angle,and vertex acceleration of the structure before and after isolation are 60%,50%,and 60%,respectively,indicating that the seismic performance of isolated structures is stronger than that of non-isolated structures.(3)The incremental dynamic analysis(IDA)is used to analyze the seismic vulnerability of the structures before and after isolation,and the numerical integration method is used to analyze the seismic risk of the structures before and after isolation.The analysis results show that the probability of mild damage,moderate damage,serious damage,and complete damage of the isolated structures under the annual earthquake is less than that of the non-isolated structures,with reduction rates of 54%,60%,56%,and 55%,respectively,indicating that isolated structures are safer than non-isolated structures.(4)On the basis of earthquake risk analysis,establish an economic loss calculation model for RC frame structures under earthquake action that meets the requirements of Chinese regulations,and calculate the annual earthquake economic loss of structures before and after isolation.The analysis results show that the annual expected economic loss of non-isolated structures is 0.5607 million yuan,while the annual expected economic loss of isolated structures is only 0.303 million yuan,a decrease of 46% compared to non-isolated structures,indicating that isolated structures cause less economic loss under the same annual earthquake action.(5)A comprehensive comparison of the seismic performance and economic losses of structures before and after isolation under the same seismic action indicate that isolation structures are superior to non-isolated structures in terms of seismic performance and economic losses.