Cyclic Response of Composite Steel Gravity Framing Connections in Multibay System-Level Tests

Abstract

This paper presents an experimental study of the seismic behavior of steel gravity frames with concrete on metal deck floor systems using multibay test specimens subjected to cyclic lateral loads. Fully bolted double-angle connections were used for the primary gravity connections under investigation. Key design variables and construction details under investigation include metal deck orientation, positioning of metal deck seams, and increased deck reinforcing ratios around the columns. Test specimens were simultaneously subjected to gravity loads and quasi-static displacement-controlled cyclic lateral loads. Results show that composite gravity connections exhibit substantial flexural stiffness, strength, and ductility, with some differences in response depending on connection design variables and construction details. Results from the system-level experiments using multibay test specimens demonstrate significant differences compared to previous subassembly tests, which indicates that the moment-resisting capacity of connections may potentially be underestimated in subassembly level tests.