Abstract

The seismic resilience of composite moment frames featuring slender concrete-filled tube (CFT) columns is herein assessed with a focus on the implications of bidirectional moment connections. As seismic design codes evolve, the need for resilient structural systems that can withstand significant seismic events becomes increasingly critical. This study employs advanced numerical modeling approaches to analyze the behavior of two three-dimensional models of office buildings designed according to Chilean seismic standards. The findings reveal that slender CFT columns exhibit satisfactory ductility and low pinching effects, even under substantial drift levels. The research underscores the importance of connection behavior, demonstrating that bidirectional moment connections enhance overall structural performance and reduce the risk of brittle failures. Additionally, the study highlights the necessity of appropriate beam-to-column stiffness ratios to ensure that beams achieve their plastic moment capacity, thereby improving ductility. Furthermore, the resilience of the slender model is confirmed through the resilience analysis, showcasing limited functionality loss post-event. Finally, the research advocates for sustainable construction practices by emphasizing the reduced environmental impact associated with the use of CFT columns. These findings contribute to the development of more effective seismic design strategies that prioritize both structural integrity and environmental sustainability. © 2025 Elsevier Ltd