Effect of Bracing Elements on Mechanics and Shear Strength of Exterior Beam-Column Joints in Moment Resisting Frames

Abstract:

Beam-column joint in moment resisting frames is very crucial particularly for non-seismically designed cases, which requires strengthening by various methods. This paper reports on shear strength reduction in exterior beam-column joints using haunch elements. Numerical analysis has been performed on exterior beam-column joint of moment resisting frame with and without a haunch element using SAP software. A parametric study has been performed for optimum haunch location (L) along the beam length (L_b) (10%, 12.5%, 15%, 20%, 25%, 40% and 50% of L_b) and the angle of the haunch element along column axis (15°, 30°, 45° and 60°). It has been observed that the optimum location of the haunch element is at 0.2L_b along the beam at an inclination of 45° with the column axis. The analysis results show that the addition of haunch element significantly reduced the joint shear strength.

• Periodical: Applied Mechanics and Materials (Volume 343)
• Pages: 15-19
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.343.15
• Online since: July 2013
• Authors: G. Appa Rao, S. Kanaka Durga
• Keywords: Beam-Column Joint, Haunch Element, Joint Shear Force, Moment Resisting Frame

References

[1] S. Pampanin and C. Christopoulo: Non-Invasive Retrofit Of Existing RC Frames Designed For Gravity Loads Only, FIB Symposium on Earthquake Resistant Structures, Ethans Greece 6-8 May (2003).

[2] Z.J. Geng, M.J. Chajes, T.W. Chou and D.Y.C. Pan: The retrofitting of reinforced concrete column-to-beam connections, Composites Science and Technology, Elsevier Science Ltd, Vol. 58 (1998), pp.1297-1305.

DOI: 10.1016/s0266-3538(98)00014-1

[3] M. Engindeniz, L.F. Kahn and A.H. Zureick: Repair and Strengthening of Reinforced Concrete Beam-Column Joints: State of the Art, ACI Structural Journal, Vol. 102, No. 2, March-April (2005), pp.1-14.

DOI: 10.14359/14269

[4] A. Ghobarah and A. Said: Shear strengthening of beam-column joints, Engineering Structures, Vol. 24 (2002), pp.881-888.

DOI: 10.1016/s0141-0296(02)00026-3

[5] G. Appa Rao, R. Eligehausen and M. AMahajan: Efficiency of Seismic Retrofit of RC Beam-Column Joints. SEC, Bangalore (2005).

[6] G. Appa Rao, M. Mahajan, M. Gangaram and R. Eligehausen: Performance of Nonseismically Designed RC Beam Column Joints Strengthened by various Schemes subjected to Seismic Loads - a Review, Journal of Structural Engineering, Vol. 35, No. 1 April-May (2008).

[7] C.V. RMurty, D.C. Rai, K.K. Bajpai and S.K. Jain: Effectiveness of Reinforcement Details in Exterior Reinforced Concrete Beam-Column Joints for Earthquake Resistance, ACI Structural Journal, Vol. 100, No. 2, March-April (2003), pp.149-156.

DOI: 10.14359/12478

[8] J. Hegger, A. Sherif and W. Roeser, Nonlinear Finite Element Analysis of Reinforced Concrete Beam-Column Connections, ACI Structural Journal, Vol. 101, No. 5, September (2004), pp.604-614.

DOI: 10.14359/13382

[9] A.G. Tsonos, I.A. Tegos, and G. Gr. Penelis: Seismic Resistance of type 2 exterior Beam-Column Joints Reinforced with inclined Bars, ACI Structural Journal, Vol. 89, No. 1, Jan-Feb (1992), pp.3-12.

DOI: 10.14359/1278

[10] S.M. Alcocer and J.O. Jirsa: Strength of RC Framed Connections Rehabilitation by Jacketing, ACI Structural Journal, Vol. 90, No. 3, May-June (1993), p.249–261.

[11] IS 1893 (Part 1): (2002), Indian standard Code of practice for Earthquake Resistant Design of Structures, Bureau of Indian Standards, New Delhi.