Prediction of the force demands of tall buildings through the enhanced pushover procedures

Abstract

Summary This paper attempts to comprehensively evaluate the accuracy of the enhanced pushover procedures in estimating the force demands of tall building structures. In this process, the efficiency of different pushover methods in taking the higher modes effect into account for the computation of the force demands is assessed. The enhanced pushover methods including the modal pushover analysis, force‐based adaptive pushover, displacement‐based adaptive pushover, consecutive modal pushover (CMP), single‐run multimode pushover (SMP), nonadaptive displacement‐based pushover, and adaptive force‐based multimode pushover procedures, as well as the conventional pushover analysis, are applied to the three special steel moment‐resisting frames to compute the internal force demands of structural members. The seismic force demands resulting from the enhanced pushover procedures are compared with those from the nonlinear response history analysis (NL‐RHA) as a benchmark solution. Furthermore, in order to evaluate approximately the degree to which the higher modes may affect deformation and force demands of tall buildings, the ratio of structural demands computed by the NL‐RHA to those obtained by the conventional pushover analysis is determined. The results demonstrate that the CMP and SMP procedures can accurately estimate the force demands of tall buildings. It is shown that the effects of higher modes on the story drifts and column shear forces and bending moments are larger than those on the other force demands.

Sensitivity of structural responses to the processing of near-fault ground motion records containing fling-step

“…Pushover analysis as a widely used analysis procedure is able to provide valuable insight into the nonlinear behavior of a structure like the lateral loading capacity of the structure subjected to seismic loads and give the damage pattern of the structure in the nonlinear range. Also, it can predict the seismic deformation demands (Fajfar, 2000) and force demands (Amini and Poursha, 2018; Goel and Chopra, 2005) of the structure by using the design spectrum of a code. In view of the simplicity and less computationally nature of the pushover procedure, it has gained growing popularity among practitioners and scholars in recent years as a tool for seismic design and evaluation of structures.…”