Research On The Influence Of Seismic Isolation Technology In High Intensity Area On The Seismic Performance Of High-rise Steel Structures

The suddenness and destructiveness of earthquakes have brought huge losses to people’s lives and property,especially in the area of high intensity earthquake damage wide and lasting for a long time.In recent years,the frequency of earthquakes on a global scale has been increasing,and high-rise buildings in cities have developed in the direction of scale and complexity,which has increased the possibility of damage to high-rise structures during earthquakes.As effective measures for passive control of structures,shock absorption technology and isolation technology can significantly improve the seismic resistance of the structure and reduce the probability of failure and destruction of structural components.With the rapid development of shock absorption and isolation technology,rubber isolation and energy dissipation brace as a new anti-seismic idea more and more get the favor of people,at present,the application of isolation technology and the reduction of vibration isolation combination of steel structure building in practical engineering is also less,and there are still some issues worthy of discussion and research in the application of seismic mitigation and isolation technology.Therefore,based on a case study of a high-rise steel structure,this paper establishes a finite element analysis model through the SAP2000 program,and conducts dynamic time history analysis of the original structure,the shock-absorbing structure,the shock-isolated structure,and the shock-absorbing and isolating combined structure.Analyze the dynamic response and isolation effects of various structures under different earthquake intensities,in order to provide some references for the selection of building seismic damping arrangements and isolation layer schemes and the joint application of seismic isolation and damping technologies.The main research contents are as follows:(1)The three-dimensional analysis model of PKPM and SAP2000 was established,and the accuracy of the original structure model was verified by comparing the structural period,total mass and interlayer shear force.The dynamic time history analysis of the three types of BRB layout structures and the original structure model under the action of frequent and rare earthquakes is carried out,and the response results of base shear force,top acceleration and floor displacement of each structure model are discussed.Analyzing the damping effects of the three types of BRB layouts in the structure,the results show that BRB layout 1 has the largest reduction in the seismic response of the structure,which is about 15% to 35%,which is the best alternative layout plan.(2)The dynamic response of high-rise steel structures with lead-core rubber bearings between floors under fortified earthquakes and rare earthquakes is studied,and three finite element models of LRB layout structures are established respectively with layer-isolated seismic layers at the bottom,middle and top of the structure.The results of the inter-story shear,floor acceleration and inter-story displacement response of the three-story seismic isolation structure and the traditional seismic structure are discussed,and the seismic isolation effects of the three LRB layout structure models are compared and analyzed.The results show that story isolation can effectively reduce the seismic response of the structure,and the lower the location of the isolation layer,the greater the reduction in the overall seismic response of the structure.At the same time,the seismic performance of the story below the isolation layer needs to be enhanced.(3)Based on the seismic action in the high-intensity area,which has huge destructive force on buildings of different structural forms and different materials,the nonlinear dynamic response of steel structures combined with layer-isolated seismic and anti-buckling bracing under rare earthquakes is analyzed.Establish an analysis model of a combined seismic reduction and isolation structure with LRB between the structural layers and below the seismic isolation layer instead of BRB,and discussed the results of the inter-story displacement,floor acceleration and inter-story shear response of the combined seismic isolation structure,the pure-story seismic isolation structure,and the traditional seismic structure.To compare and analyze the changes in the seismic reduction and isolation effect of the higher intensity earthquake action on the combined seismic reduction and isolation structure,and the results show that the combined shock-absorbing and isolating structure has better shock-absorbing performance,especially in high-intensity areas,which can provide more safety reserves for the structure.