This paper presents an analytical assessment of the robustness of concrete deck-steel beam composite floor systems with shear connectors under the assumption that an interior column has been removed. The study provides an insight into the behavior and failure modes of the simple shear connections and the composite floor system. The analyses of the simple shear connection indicate that the loads are primarily resisted by cable action, resulting in increasing tensile forces in the beam that lead to the failure of the connection. The ultimate rotation sustained by the shear connection prior to failure under the column removal scenario is about 0.09 radians. The analyses of the composite floor system show that the floor deck contributes significantly to the floor system response through: (1) diaphragm action to prevent the exterior column from being pulled inward, and (2) membrane action primarily through the mesh reinforcement and metal deck. The analyses show that the capacity of the analyzed floor system under the column removal scenario is less than the load specified by the General Services Administration s Progressive Collapse Analysis and Design Guidelines for New Federal Office Buildings and Major Modernization Projects. This indicates that this floor system is vulnerable to collapse under this scenario and that special precautions should be made when designing composite floor systems with shear connectors if intermediate columns are deemed vulnerable to failure.
Citation: Journal of Structural Engineering--ASCE
Pub Type: Journals
composite floor systems, disproportionate collaspe, finite element analysis, progressive collaspe, structural robustness