Analytical Extension of Higher Modes Participation in Estimation of Seismic Response Parameters of Tall Hybrid Framed Tubes comprising Mega Zipper Elements

This paper presents a computational approach to the analytical performance of modal pushover method (MPA) in predicting nonlinear response parameters of tall buildings compriding hybrid framed tube with large scale zipper elements. The accuracy of the results based on MPA is evaluated by comparing the benchmark responses obtained through conducting two sets of nonlinear time history analyses (NLRHA). Also, the effect of higher modes on the structural response parameters is measured by considering three computational vectors of the ordered lateral loading prepared according to the participation of the basic mode as well as the first 3 and 5 transitional modes, separately. In this study, the determination of the target displacement in MPA was set based on the results of NLRHA under two groups of near and far field records. The variation range of response parameters of the three high-rise 30storey studied structures was evaluated based on conducting a series of MPA as well as NLRHA analyses. The computational outputs of the MPA are compared with the results of the NLRHA (as exact values) and the standard error percentage is estimated. Evaluation of the results represented in this study demonstrates the relatively desirable computational capability of the MPA method in predicting the behavior characteristics of tall building structures with symmetric and regular rigid skeleton at plan and height. Moreover, it was observed that the presence of large-scale zipper elements in resistant system can reduce the seismic response parameters and also relatively increases the overall dynamic stability of high-rise structural skeleton.