On the accuracy of enhanced pushover procedures for seismic performance evaluation of code-conforming RC moment-resisting frame buildings subjected to pulse-like and non-pulse-like excitations

Abstract

In this paper, the applicability and validity of enhanced pushover procedures in estimating the seismic demands of mid- and high-rise reinforced concrete (RC) building frames under pulse-like near-fault ground motions having forward-directivity and fling-step effects as well as non-pulse-like near-fault and far-fault ground motions are assessed through the comparison with the nonlinear response history analysis (NL-RHA). The enhanced pushover procedures including the modal pushover analysis (MPA), force-based adaptive pushover (FAP), displacement-based adaptive pushover (DAP), extended N2 method (EN2), single-run multi-mode pushover (SMP), and non-adaptive displacement-based pushover (NADP) procedures, as well as a conventional pushover method based on the first mode of the structure, are performed. To this end, three plan-symmetric buildings including the 9-, 12-, and 18-story RC frames designed in accordance with the provisions of ASCE 710 and ACI 318-14 are examined. The engineering demand parameters considered are the interstory drift ratios and story shears, which are representatives of the deformation and force demands, respectively. Additionally, the seismic performance of the RC buildings is assessed using the conventional and the enhanced multi-modal pushover procedures in accordance with the systematic evaluation scheme of the ASCE 41-17 standard. The comparative evaluation demonstrates that the accuracy of the NSPs varies with the type of the ground motions. Some methods result in satisfactory performance for pulse-like ground motions, some for non-pulse-like ones, and some for both of them. All in all, the MPA, EN2, and SMP procedures provide a relatively better prediction of the seismic demands of RC building frames.