Analytical Study of Interior Rigid Bents Arrangement on Seismic Response of Tall Buildings

In this research, the performance abilities associated with tube type lateral load resistant framed systems are studied in order to assess the seismic response parameters of steel tall buildings under both far and near-field records. For this purpose, four 30 story structural models with separated framed tube-based skeletons were selected and designed. The structural models have been designed according to the Iranian seismic code 2800 (4^th edition). The structural response parameters have been computed and obtained by conducting a number of non-linear dynamic time history analyses. Based on the analytical results obtained from nonlinear analyses, the values of maximum inter-story drift, story acceleration and velocity, dynamic base shear, configuration of plastic hinges mechanism, shear lag phenomena and residual drift were assessed and investigated. Yet, the results have been discussed and compared with the life safety and collapse prevention performance limits, as recommended by FEMA 356. Findings from this study reveal that mean maximum demands and the dispersion in the peak values were considerably higher for near-fault records than far-fault motions. The obtained results indicate the fact that an appropriate arrangement and bundled configuration of interior rigid frames could remarkably reduce the appearance of shear lag phenomenon almost up to 70% as compared to the corresponding results with basic framed tube.