Evaluation of steel frame beam-to-column connection strengthening to resist progressive collapse

A primary structural component, in a building, may collapse if the imposed load goes beyond its capacity during an accidental action. Code agencies such as: General Services Administration GSA and Department of Defense DoD established guidelines for progressive collapse mitigation. It is required not only to design buildings capable to resist progressive collapse, but also to retrofit the existing ones. The beam-to-column moment resisting connections of a building frame are responsible for the safe transfer of loads from a member to another; and in turn, play an important role in progressive collapse resistance. In this study, two-scale structure-connection modeling approach has been employed to assess the progressive collapse susceptibility of a symmetric steel moment resisting frame structure. Structure-based and connection-based 3D finite element models have been established and studied, where different configurations have been considered to strengthen both flushed and extended end plate beam-to-column moment connections. The alternate path method with the nonlinear static analysis has been performed in accordance with Unified Facilities Criteria UFC of the DoD. The study revealed an evaluation for the effectiveness of connection strengthening for progressive collapse mitigation. © 2014 Medwell Journals. All rights reserved.