Performance evaluation of new steel frame buildings for seismic loads

Abstract

SUMMARYThe damage observed after the Northridge Earthquake exposed a weakness of design and construction procedures and led to the development of performance-based guidelines for design of new steel frame structures. As part of Phase 2 of the FEMA=SAC project, this study focused on performance prediction of new steel special moment resisting frame buildings assumed to be built after the Northridge earthquake. A total of 26 post-Northridge buildings that represent typical steel SMRF buildings based on the new seismic code (1997 NEHRP) and pre-qualiÿed post-Northridge connections were designed. Then, the analytical building models considering the e ects of ductile connections, panel zone deformation and interior gravity frames were developed and subjected to sets of 20 SAC ground motions representing the 2=50 and 50=50 hazard levels. A new procedure that allows the design professional to determine the conÿdence level for achieving a given performance objective is presented. Using the drift demand and capacities, conÿdence levels that post-Northridge buildings will satisfy the collapse prevention and immediate occupancy performance level are calculated. All of the post-Northridge buildings exhibit a high conÿdence of performing well in future earthquakes.

Direct Estimation of Seismic Demand and Capacity of Multidegree-of-Freedom Systems through Incremental Dynamic Analysis of Single Degree of Freedom Approximation

“…To illustrate our methodology, we will perform IDA for a centreline model of a 9-storey steel-moment resisting frame designed for Los Angeles according to the 1997 NEHRP provisions (Lee & Foutch, 2002). The model incorporates ductile members, shear panels and realistically fracturing Reduced Beam Section connections, while it includes the influence of interior gravity columns and a first-order treatment of global geometric nonlinearities (P-∆ effects).…”

The Influence of Gravity Loads on the Seismic Design of RBS Connections

“…Conversely, condition (19), depending on its fulfilment or not, can be used to discern if the second plastic hinge develops in the left "dog-bone" or in the intermediate beam section.…”

“…These damages were mainly due to the failure of welded beam-to-column connections. For these *Address correspondence to this author at the University of Salerno, Via Giovanni Paolo II, Fisciano (SA), Italy; Tel: +39 098 963421; Fax: +39 089968764; E-mail: r.montuori@unisa.it reasons ARBED waived any licensing fees and claims and RBS connections started to be investigated by a lot of researchers [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29].…”

Research plan for the study of seismic behavior and design of deep, slender wide flange structural steel beam-column members

“…A number of investigators have conducted nonlinear response history analyses of steel moment resisting frames (MacRae et al, 1990;Krawinkler, 1999, 2000;Medina and Krawinkler, 2003;Zareian and Krawinkler, 2007, Luco and Cornell, 2000, Lee and Foutch, 2000, 2002aLignos and Krawinkler, 2009). As part of the SAC project, Luco and Cornell (2000) and Lee and Foutch (2002b) assessed the effects of brittle connection fractures on the behavior of archetype steel moment resisting frame structures ranging in height from 2-to 20-stories, with pre-Northridge connections, at various levels of ground motion intensity.…”

“…It has been shown both analytically Zareian and Krawinkler, 2007;Lignos and Krawinkler, 2009) and experimentally (Lignos et al, 2010(Lignos et al, , 2011dSuita et al, 2008) that the capping point is critical for assessing the collapse potential of moment resisting frames Lignos and Krawinkler, 2009;Lignos et al, 2011a). Lee and Foutch (2002a) concluded that all of the buildings with postNorthridge connections showed a high capacity-to-demand ratio ranging from 2.0 to 4.0, depending on frame configuration and height. As a result, it was decided that post-Northridge connections should exhibit good performance in future seismic events.…”