Performance-based Seismic Design Method And Application In Seismic Evaluation Of Tall Building Hybrid Structure

In China, tall building hybrid structures (TBHS), which are composed with steel frames and concrete core-tubes (shear-walls) or with composite steel frames and concrete core-tubes (shear-walls), have been widely applied. It is rational to research the seismic response of the TBHS. Presently, the seismic design has been shifted from force-based design to performance-based design or displacement-based design. In this thethis, combined with the research project"Research on the behavior of the tall building hybrid structure"financed by the Natural Science Foundation of China (NSFC), several key problems on performance-based design are studied.1. The higher mode effect cannot always be ignored in pushover analysis of tall building hybrid structures (TBHS). Therefore, in this thethis, an improved multi-mode pushover analysis, which combines the advantage of the modal pushover analysis (MPA) and the adaptive pushover analysis (APA), has been proposed to take the higher mode effect and history of load into account. In the multi-mode pushover analysis procedure, the multiple degree-of-freedom (MDOF) system can approximately be decomposed into equivalent single degree-of-freedom (ESDOF) system of multi-mode. The response of each modal pushover analysis can be attained by using adaptive load pattern when the structure enters into nonlinear stage.2.Nonlinear dynamic analysis of bilinear single degree-of-freedom (SDOF) system under 177 strong earthquake records which are classified by shearing wave velocities according to the China Code for Seismic Design of Buildings (GB50011-2001) is presented. Based on the comprehensive statistical analysis of inelastic displacement ratios, the regression equations ofμ- R - T about the strength reduction coefficient and inelastic displacement ratios are obtained. The effects of soil condition, earthquake magnitude, epicenter distance, damp ratios and hysteretic characteristics are considered in detail.3. The displacement demand (target displacement) of pushover analysis by adopting capacity spectra method is discussed. In this paper, based on the elastic spectra in GB50011-2001, an improved capacity spectra curve is developed by using the equations ofμ? R ? Tof different soil conditions. The displacement demand (target displacement) of each modal pushover analysis is obtained by using the improved capacity spectra method. The seismic response of different height TBHS are...