N-M AND M-K RELATIONSHIPS OF REINFORCED CONCRETE COLUMNS IN TEC2018

Year 2018, Volume: 19 Issue: 2, 499 - 513, 30.06.2018

Ayten Günaydın , Hande Gökdemir

https://doi.org/10.18038/aubtda.402180

Abstract

Reinforced concrete
elements subject to moment, shear and axial force due to different level of
static and dynamic loads based on their location and material characteristics.
These elements disseminate the loads based on their connections with other
elements. In particular, each column in the structure exhibits "combined
bending" behavior together with the resulting moment of the eccentric
axial force exerted. In the case of the axial load acting on one of the
symmetry axes (x or y axis) the uniaxial bending, and the axial load acting out
of the symmetry axis, biaxial bending occurs. Also, since the structures are
composed of two directional frames and slabs, the reinforced concrete columns
are subject to combined bending effects in both directions. Therefore, the
determination of the ultimate strength and behavior of the reinforced concrete
columns depends on the interaction of axial force (N) and moment (M). In this
study, the N-M diagram of reinforced concrete columns is given considering the
section geometry, concrete and steel reinforcement strength and placement of
the longitudinal reinforcements. The given N-M diagrams are prepared based on
the axial force limits in codes. In addition, the N-e diagram showing the axial
force and eccentricity relation of reinforced concrete column sections is
given. Ductility ratios are given by plotting the moment curvature diagrams of
the column sections at various axial force levels of the N-M diagram.

Keywords

N-M interaction diagram, axial force, eccentricity, bending moment-curvature diagram

References

• [1] ACI Committee 318. Building Code Requirements for Structural Concrete (ACI 318-14). American Concrete Institute, Farmington Hills, MI, 2014.
• [2] FEMA 356. Prestandard and Commentary for the Seismic Rehabilitation of Buildings. FEMA, Washington, DC, USA, 2000.
• [3] EC8. Design Provisions for Earthquake Resistance of Structures. Pub. ENV-2003-2, Comite Europeen de Normalization, Brussels, 2003.
• [4] TDY 2007. Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik. Bayındırlık ve İskan Bakanlığı (in Turkish), Ankara, 2007.
• [5] TDY 2018. Türkiye Bina Deprem Yönetmeliği. Çevre ve Şehircilik Bakanlığı (in Turkish), Ankara, 2018.
• [6] Furlong, RW. Concrete columns under biaxial eccentric thrust. ACI Journal 1979; 1093-1118.
• [7] Hsu, CT. Biaxial loaded L-shaped reinforced concrete columns. ASCE J Struct Eng 1985; 111(12): 2576-2595.
• [8] Hsu, CT. Channel-shaped reinforced concrete compression members under biaxial bending. ACI Struct J 1987; 84: 201-211.
• [9] Hsu, CT. T-shaped reinforced concrete members under biaxial bending and axial compression. ACI Struct J 1989; 86(4): 460-468.
• [10] Rangan BV. Strength of reinforced concrete slender columns. ACI Struct J 1990. 87(1): 32-38.
• [11] Ersoy U, Özcebe G. Betonarme. 5. Basım, Ankara: Seçkin Yayıncılık, 2017.
• [12] Berktay İ. Betonarme I, Taşıma Gücü ve Kesit Hesapları.3. Basım, İstanbul: İnşaat Mühendisleri Odası, 2003.
• [13] Orbay A. Betonarme I. İstanbul: Birsen Yayınevi, 2005.
• [14] TS 500, Betonarme Yapıların Tasarım ve Yapım Kuralları, Türk Standartları Enstitüsü (in Turkish), Ankara, 2000.
• [15] Ersoy U. Özcebe G. Sarılmış betonarme kesitlerde moment–eğrilik ilişkisi analitik bir irdeleme, Teknik Dergi 1998; 9(44): 1799-1827.