Critical Assessment of Estimation Procedures for Floor Acceleration Demands in Steel Moment-Resisting Frames

Abstract

Performance-based earthquake engineering has created the need for practical ways to assess the response of non-structural components (NSCs), which may be affected by deformation and/or acceleration demands of the superstructure. In the research study detailed in this paper, peak floor accelerations (PFAs) and floor response spectra (FRS) are computed using non-linear time history analysis (NTHA) for a comprehensive suite of 30 steel moment-resisting frame (MRF) archetypes, designed in accordance to Eurocode 8, considering different levels of non-linear seismic demand. The mean trends observed were compared with the most recent approaches proposed in the literature for prediction of acceleration demands. It was found that for PFAs, the available methods provide accurate predictions of the actual structural response under elastic and inelastic demands. However, the estimation procedures for the FRS yielded relevant differences in comparison to the observed elastic and inelastic responses, which entails the need for further development of such methods. It was also concluded that the existing PFA and FRS estimation methodologies present in several guidelines for seismic design and/or assessment do not provide reliable estimates of the acceleration demands incurred by the building. This highlights the very important need for an improvement of these codified procedures for a more reliable prediction of the seismic structural response.

Influence of Beam-to-Column Connections in Seismic Vulnerability Assessment of Steel Structures

“…The present study is meant to provide a further contribution on the evaluation of the influence of the explicit modeling of beam-to-column connections in the seismic vulnerability assessment of steel MRFs; in addition, the results of the undertaken nonlinear dynamic analyses are used here to estimate the seismic demand on non-structural elements (NSEs) via floor absolute acceleration spectra [6].…”

Seismic Acceleration and Displacement Demand Profiles of Non-Structural Elements in Hospital Buildings

“…In some cases, simple mitigation details can guarantee the achievement of performance objectives for each limit state, while for more complex systems an accurate design of connections and bracing systems is required [8,9]. However, the estimation of the seismic demand for NSEs is not a simple task, as demonstrated by numerous past research studies dealing with the evaluation of simplified methodologies to predict peak floor acceleration profiles, interstorey drifts, and floor response spectra [10][11][12][13][14][15][16]. National and international codes provide some simplified formulations to calculate the seismic demand on NSEs and, consequently, the equivalent static force to be applied at the center of mass of the NSE to perform the design and/or the assessment [1,2].…”

“…National and international codes provide some simplified formulations to calculate the seismic demand on NSEs and, consequently, the equivalent static force to be applied at the center of mass of the NSE to perform the design and/or the assessment [1,2]. However, recent studies [11][12][13][14][15][16] pointed out the inaccuracy of such formulations and the need for further investigations to improve the prediction of peak floor acceleration, interstorey drifts, and floor response spectra.…”