PRACTICAL METHOD FOR ANALYSIS AND DESIGN OF SLENDER REINFORCED CONCRETE COLUMNS SUBJECTED TO BIAXIAL BENDING AND AXIAL LOAD
DOI:
https://doi.org/10.11113/mjce.v22.15803Keywords:
Slender, Bi-axial, bending, RC column, magnifier, eccentricity, encased composite columns, composite columns,Abstract
Reinforced and concrete-encased composite columns of arbitrarily shaped cross sections subjected to bi axial bending and axial load are commonly used in many structures. For this purpose, an iterative numerical procedure for the strength analysis and design of short and slender reinforced concrete columns with a square cross section under biaxial bending and an axial load by using an EC2 stress-strain model is presented in this paper. The computational procedure takes into account the nonlinear behavior of the materials (i.e., concrete and reinforcing bars) and includes the second order effects due to the additional eccentricity of the applied axial load by the Moment Magnification Method. The ability of the proposed method and its formulation has been tested by comparing its results with the experimental ones reported by some authors. This comparison has shown that a good degree of agreement and accuracy between the experimental and theoretical results have been obtained. An average ratio (proposed to test) of 1.06 with a deviation of 9% is achieved.References
Furlong RW. (1979) Concrete columns under biaxially eccentric thrust. ACI Journal October :1093–118.
Brondum-Nielsen T. (1986) Ultimate flexural capacity of fully prestressed, partially prestressed, arbitrary concrete sections under symmetric bending. ACI Journal 1986;83:29–35.
Hsu CTT. Biaxially loaded L-shaped reinforced concrete columns. Journal of Structural Engineering ASCE 1985;111(12):2576–95.
Hsu CTT. Channel-shaped reinforced concrete compression members under biaxial bending. ACI Structural Journal 1987;84:201–11.
Dundar C. Concrete box sections under biaxial bending and axial load. Journal of Structural Engineering 1990;116:860–5.
Rangan BV. Strength of reinforced concrete slender columns. ACI Structural Journal 1990;87(1):32–8.
Building code requirements for structural concrete (ACI 318-99). Detroit (MI): American Concrete Institute (ACI); 1999.
Dundar C, Sahin B. Arbitrarily shaped reinforced concrete members subjected to biaxial bending and axial load. Computers and Structures 1993; 49: 643–62.
Whitney CS. Plastic theory of reinforced concrete design. Transactions, ASCE 1940; 107:251–60.
Rodriguez JA, Aristizabal-Ochoa JD. Biaxial interaction diagrams for short RC columns of any cross section. Journal of Structural Engineering 1999; 125(6):672–83. Fafitis A. Interaction surfaces of reinforced-concrete sections in biaxial bending.
Journal of Structural Engineering 2001; 127(7):840–6.
Hong HP. Strength of slender reinforced concrete columns under biaxial bending. Journal of Structural Engineering 2001;127(7):758–62.
Saatcioglu M, Razvi SR. High-strength concrete columns with square sections under concentric compression. Journal of Structural Engineering 1998;124(12):1438–47.
Furlong RW, Hsu CTT, Mirza SA. Analysis and design of concrete columns for biaxial bending- overview. ACI Structural Journal 2004;101(3):413–23.
Mirza SA. Parametric study of composite column strength variability. Journal of Constructional Steel Research 1989;14:121–37.
Lachance L. Ultimate strength of biaxially loaded composite sections. Journal of Structural Division, ASCE 1982;108:2313–29.
Chen SF, Teng JG, Chan SL. Design of biaxially loaded short composite columns of arbitrary section. Journal of Structural Engineering 2001;127(6):678–85.
Sfakianakis MG. Biaxial bending with axial force of reinforced, composite and repaired concrete sections of arbitrary shape by fiber model and computer graphics. Advances
in Engineering Software 2002; 33:227–42.
Kent DC, Park R. Flexural members with confined concrete. Journal of Structural Division ASCE 1971; 97(7):1969–90.
Sheikh SA, Uzumeri SM. Analytical model for concrete confinement in tied columns.
Journal of Structural Division ASCE 1982;108(12): 2703–22.
Saatcioglu M, Razvi SR. Strength and ductility of confined concrete. Journal of Structural Engineering 1992; 118(6):1590–607.
Chung HS, Yang KH, Lee YH, Eun HC. Stress–strain curve of laterally confined concrete. Engineering Structures 2002; 24:1153–63.
Dundar C, Tokgoz S, Tanrikulu A.K, Baran T, Behavior of reinforced and concreteencased composite columns subjected to biaxial bending and axial load. Building and
environment 2007.
Algerian seismic code, RPA 99-03, National Research Center for applied earthquake engineering, Algeria, 1999 modified 2003, (in French).
Demagh, K., Simplified Method for Analysis and Design of Biaxially Loaded Reinforced Concrete columns’. Design and Sustainability of Structural Concrete in
the Middle East with Emphasis on High Rise Buildings, American Concrete Institute-KC second International Conference, March 12-14, 2007, State of Kuwait, pp. 113-124;
Demagh, K., Simplified Method for Analysis and Design of Biaxially Loaded Reinforced Concrete columns’, ACBM-ACI, Lahore, Pakistan, 12-14, 2007, pp 773-781.
Hsu C.T.T., Analysis and Design of Square and Rectangular Columns by Equation of Failure Surface, ACI Structural Journal, Technical paper, title no 85-S20, 1988, pp 167-179.
Commission of the European Communities (CEC). Design of composite steel and concrete structures. Brussels: Eurocode 4; 1984.
