Robustness of Composite Floor Systems with Shear Connections: Modeling, Simulation, and Evaluation

Abstract

This paper presents a computational investigation of the robustness of a typical concrete deck–steel beam composite floor system with simple shear connections in the event that a center column has been removed. The study provides insight into the behavior and failure modes of simple shear connections and composite floor systems comprised of such connections. Analyses of a connection subassemblage indicate that loads are primarily resisted by cable action of the beams after column loss resulting in increasing tensile forces in the beams and connections that could eventually precipitate failure. Simulation results show that the floor deck contributes significantly to the floor system response through: diaphragm action to prevent the exterior columns from being pulled inward and membrane action primarily through the reinforcement mesh and metal deck. The analyses indicate that the capacity of the analyzed floor system under the column removal scenario is significantly less than the load specified by the General Services Administration’s current progressive collapse guidelines. This suggests that applying these guidelines, the composite floor system studied would be vulnerable to collapse if a center column is lost.