Structural Behavior of RC Beam-Column Subassemblages under a Middle Column Removal Scenario
Publication: Journal of Structural Engineering
Volume 139, Issue 2
Abstract
Six RC beam-column subassemblages, consisting of two single-bay beams, one middle joint, and two end column stubs, were quasi-statically tested under a middle column removal scenario. The tests were aimed at investigating whether there are alternate load paths that can mitigate progressive collapse. With adequate axial restraints, both compressive arch action (CAA) and catenary action could be mobilized, significantly increasing the structural resistance beyond the beam flexural capacity. The effects of the top and bottom reinforcement ratios at the joint interfaces and beam span-to-depth ratio on structural behavior were studied. The results show that CAA is more beneficial to subassemblages with a short span-to-depth ratio and a low reinforcement ratio, whereas catenary action is more favorable to subassemblages with a large span-to-depth ratio and a high reinforcement ratio, particularly the top reinforcement ratio. As the last defense mechanism to prevent structural collapse, the development of catenary action is highlighted. The onset of catenary action corresponds to the transition of beam axial force from compression to tension, typically occurring at a central deflection around one beam depth in the tests if no shear failure precedes catenary action. At the catenary action stage, prior to fracture of the bottom bars, structural resistance is contributed by both beam axial tension from longitudinal reinforcement and shear force because of dowel action. If the contribution from rising axial tension exceeds the loss as a result of declining shear force, the structural resistance will still keep on increasing until the fracture of the top bars. Finally, the authors suggest a deformation criterion to determine the catenary action of RC subassemblages; i.e., when the deflection at the middle joint attains 10% of the total beam span length, catenary action capacity is reached. The conservatism of this criterion for design purposes is also discussed.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors gratefully acknowledge the research funding provided by the Defence Science & Technology Agency, Singapore.
References
American Concrete Institute (ACI). (2004). “ACI detailing manual.” ACI SP-66(04), Farmington Hills, MI.
American Concrete Institute (ACI). (2005). “Building code requirements for structural concrete.” ACI 318-05, Farmington Hills, MI.
ASCE. (2005). Minimum design loads for buildings and other structures, ASCE, Reston, VA.
Department of Defense (DoD). (2010). “Design of buildings to resist progressive collapse.” UFC 4-023-03, Washington, DC.
Ellingwood, B., and Leyendecker, E. V. (1978). “Approaches for design against progressive collapse.” J. Struct. Div., 18(3), 413–423.
European Committee for Standardization (CEN). (2006). “Eurocode 1: Actions on structures. Part 1–7: General actions—Accidental actions.” EN 1991-2-7, Brussels.
General Services Administration (GSA). (2003). Progressive collapse analysis and design guidelines for new federal office buildings and major modernization projects. Washington, DC.
Gurley, C. R. (2008). “Progressive collapse and earthquake resistance.” Pract. Period. Struct. Des. Constr., 13(1), 19–23.
Izzuddin, B. A., Vlassis, A. G., Elghazouli, A. Y., and Nethercot, D. A. (2008). “Progressive collapse of multi-storey buildings due to sudden column loss—Part I: Simplified assessment framework.” Engineering Structures, 30, 1308–1318.
Orton, S., Jirsa, J., and Bayrak, O. (2009). “Carbon fiber-reinforced polymer for continuity in existing reinforced concrete buildings vulnerable to collapse.” ACI Struct. J., 106(5), 608–616.
Park, R., and Gamble, W. L. (2000). Reinforced concrete slabs, Wiley, New York.
Sasani, M., Bazan, M., and Sagiroglu, S. (2007). “Experimental and analytical progressive collapse evaluation of actual reinforced concrete structure.” ACI Struct. J., 104(6), 731–739.
Sasani, M., Kazemi, A., Sagiroglu, S., and Forest, S. (2011). “Progressive collapse resistance of an actual 11-story structure subjected to severe initial damage.” J. Struct. Eng., 137(9), 893–902.
Sasani, M., and Kropelnicki, J. (2008). “Progressive collapse analysis of an RC structure.” Struct. Des. Tall Spec. Build., 17(4), 757–771.
Su, Y. P., Tian, Y., and Song, X. S. (2009). “Progressive collapse resistance of axially-restrained frame beams.” ACI Struct. J., 106(5), 600–607.
Yi, W. J., He, Q. F., Xiao, Y., and Kunnath, S. K. (2008). “Experimental study on progressive collapse-resistant behavior of reinforced concrete frame structures.” ACI Struct. J., 105(4), 433–439.
Yu, J., and Tan, K. H. (2010a). “Experimental study on catenary action of RC beam-column sub-assemblages.” Proc., 3rd Int. FIB Congress and Exhibition, Precast/Prestressed Concrete Institute, Chicago.
Yu, J., and Tan, K. H. (2010b). “Progressive collapse resistance of RC beam-column sub-assemblages.” Proc., Design and Analysis of Protective Structures, Defence Science & Technology, Singapore, 74–83.
Yu, J., and Tan, K. H. (2011). “Experimental and numerical investigation on progressive collapse resistance of reinforced concrete beam column sub-assemblages.” Eng. Struct., (in press).
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 139 • Issue 2 • February 2013
Pages: 233 - 250
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Aug 31, 2011
Accepted: May 24, 2012
Published online: May 26, 2012
Published in print: Feb 1, 2013
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.