| This thesis presents the results of a study on the seismic performance of a 21-storey steel frame building in Shanghai. This building was asymmetric-planned and designed to resist lateral force mainly by square concrete-filled steel tube (SCFST) columns.Detailed linear three-dimensional dynamic analyses were conducted to determine the aberration between the responses of the structure using various assumptions of sectional rigidity, which were specified by codes and specifications (which are CECS159:2004, CECS28:90, EC4 (1994), AIJ (1980) and AISC-LRFD99). The results show that dynamic characteristics of structures using different sectional assumptions are nearly the same and the aberrations between the responses of these structures are minor and negligible in the stage of elastic deformation.Simplified nonlinear static analyses were employed to investigate seismic performance of both the structure and a 1/15 shaking-table test model. The evaluation is focused on similarities of the nonlinear responses between the prototype structure and the scaled model in the stage of elasto-plastic deformation. The displacement and floor drift ratio of 5th18th stories meet the similarity relations. Displacement and drift ratio below 5th floor exhibit deviation from the assumed similarity coefficient. Further comparison on the base reactions and corresponding stress which is extremely intensive show that the aberration between the prototype structure and the scaled model increased dramatically on account of nonlinear deformation of the column members. Improved capacity spectrum method using inelastic demand spectrum and various ductility factors was engaged to investigate the target displacement of the structure subjected to seldomly occurred earthquake. |
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