Seismic Analysis Of An Out-of-code High-rise Building In Chongqing And Analysis Of Seismic Resistance Influence Factors Of Girder Ttransfer Story Structure

The shortage of urban land resources is a growing problem because of the urban construction which is accelerated by the rapid development of economy. The high-rise building with complicated structure system is more widely used in city. The high-rise building with transfer story can provide adequate space at bottom and the superstructure can be used as residence or office. The number of the high-rise building with the characters of height exceeding limitation and plane irregularity is continuously increasing. There are strong reaction, large stress and deformation under the earthquake in these buildings.and some difficulties in controling the performance index. In order to improve the reliability and security of structural anti-seismic design for high-rise buildings, it is necessary to inspect the transfinite project and do structural analysis by codes strictly. The primary contents of this paper are as follows: choose the appropriate method for seismic analysis, judging the seismic performance level of the Structure and providing some relevant protective measures for the weakness of structures.The research object in this paper is an out-of-code high-rise building with the characters of B grade and high transfer story in Chongqing. Do the performance-based seismic design for the structure, the calculation results are analyzed to grasp the extent of structural deformation and damage, and ensure that the structure can reach the seismic fortification goal. In order to determine how the girder transfer floor affect the seismic performance of the structure, It is presented at the latter part of this paper that the analysis of how these factors such as he stiffness of the transfer beam, thickness of transfer floor slab, and the stiffness of a shear wall structure with bottom braced frame affect the vibration performance and seismic performance of the structure. The specific works and the main conclusions of this paper are as follows:Midas Building and ETABS structural analysis software are used for response spectrum analysis of the structure, the result of ETABS software is used for comparison and analysis. Analyze the rationality of the results such as period ratio, displacement ratio by the codes and to judge the rationality of the analysis model. Midas Building is used for the elastic time history analysis. Contrastive results show that the results of elastic time history analysis are smaller than the results of the elastic response spectrum. We should choose the results of the elastic response spectrum for the structural design.Midas Building and ETABS structural analysis software are used for the analysis of structural performance under moderate earthquake. According to the structural performance indices and performance of the key structural members to judge whether the structure can reach the seismic performance goal of "repairable under moderate earthquake".Midas Building structural analysis software is used for the Pushover analysis of structure under major earthquake. Analyze the rationality of the results by the comparison to the results of response spectrum analysis and the codes. To make sure the weakness of structures after the analysis of the distribution of plastic hinge of framework and shear wall at performance point and the final status, at last to judge whether the structure can reach the seismic performance goal of " no collapse under major earthquakes ".The stiffness of transfer beam and box support layer and the thickness of transfer floor slab are changed in original model for new analysis model. The analysis results such as structural period, base shear, inter-story displacement angle show the influences on the vibration and seismic performance of the structure, and some reference suggestions for engineering design are provided.