Research On Seismic Performance Of A Reinforced Concrete Frame-shear Walls Isolated Structure With Large Chassis

In recent years,due to the requirement of building function,the high-rise buildings with large chassis were be applied widely.This large chassis structure with lateral stiffness varying in vertical direction are vertical irregular structure.Damage previous survey showed that,the seismic damage is still quite serious in the large chassis structure with use the design method of traditional seismic.Currently,isolation technology can be used to solve this problem.According to the Chineses current seismic design code GB50011-2010,the isolation layer can be set above the top of large chassis.Thus,upper of isolation layer is isolated structure,while the lower of isolation layer is seismic structure,which are belong to two different structural forms.Under the earthquake,there are some significant differences compared with the structural dynamic response of base isolation system,and there is widespread worry about the seismic safety of the sub substructure.Based on this,choose the high-gise reinforced concrete frame-shear walls isolated structure to study.The main research work includes:the analysis and design of isolated structure,the dynamic elastic-plastic analysis of isolated structure and the structure failure analysis of isolated structure:(1)According to the requirements of the "Code for seismic design of buildings "(GB50011-2010),design a 11-story high-rise reinforced concrete frame-shear wall structure of large chassis with single tower.The finite element software(ETABS)is applied to design the RC frame-shear walls isolated structure with large chassis under the fortification intensity of 8(0.2g).It provide a numerical model for the study of elastic-plastic analysis and structural failure of isolated structure.(2)For the reinforced concrete frame-shear walls isolated structure with large chassis,a a study is carried out on seismic performance of this structure when the lateral stiffness of large chassis change.Build three model of reinforced concrete frame-shear walls isolated structure by keeping the component size,strength and so on remains unchanged,and only changing the storey height of large chassis.Then apply elasto-plastic dynamic analysis to this model under rare earthquake,and comparative analysis the seismic response of three different model.Based on the analysis results,we recommend that it need to increase the strength and ductility of beam member which in the chassis and the story above the isolation layer,and it also need to increase the strength and ductility of column member which in the chassis and the top floor.(3)Using the incremental dynamic analysis to study the damage failure model of three large chassis reinforced concrete frame-shear walls isolation structure model.The limit IDA curve of maximum inter-story drift,maximum horizontal deformation of the isolation layer,the maximum tensile and maximum compressive stress of the isolation bearing of three isolated structure model were analyzed.The results show that,with the decrease of lateral stiffness of the chassis,the maximum pressure of isolation bearing and the story drift of chassis were increased.Based on the analysis results,we recommend that it need to increase the lateral stiffness of large chassis to ensure that the damage inactivation of the large chassi happened after the lateral stiffness of isolation layer and upper tower building.