Seismic Performance of RC Frames Irregular in Elevation Designed Based on Iranian Seismic Code

Authors

1 Assistant Professor, Department of Civil Engineering, University of Kurdistan, Iran

2 M.Sc., Student of Civil Engineering, University of Kurdistan, Iran

Abstract

Setback in elevation of a structure is a special irregularity with considerable effect on its seismic performance. This paper addresses multistory Reinforced Concrete (RC) frame buildings, regular and irregular in elevation. Several multistory Reinforced Concrete Moment Resisting Frames (RCMRFs) with different types of setbacks, as well as the regular frames in elevation, are designed according to the provisions of the Iranian national building code and Iranian seismic code for the high ductility class. Inelastic dynamic time-history analysis is performed on all frames subjected to ten input motions. The assessment of the seismic performance is done based on both global and local criteria. Results show that when setback occurs in elevation, the requirements of the life safety level are not satisfied. It is also shown that the elements near the setback experience the maximum damage. Therefore it is necessary to strengthen these elements by appropriate method to satisfy the life safety level of the frames.

Keywords


[1] Penelis, G.G., Kappos, A.J. (1997). “Earthquake-resistant concrete structures”. Chapman & Hall, E & FN SPON, London,

[2] Penelis, G.G., Sarigiannis, D., Stavrakakis, E., Stylianidis, K.C. (1988). “A statistical evaluation of damage to buildings in the Thessaloniki, Greece, earthquake of June 20, 1978”. In Proceedings of the 9th world conference on earthquake engineering, Japan.

[3] Spyropoulos, P.J. (1982). “Report on the Greek earthquakes of February 24&25, 1981”. Concrete International, ACI, Vol. 4, pp. 11–15.

[4] Humar, J.L., Wright, W. (1977). “Earthquake response of steel-framed multistory buildings with set-backs”. Earthquake Engineering & Structural Dynamics, Vol. 5, No. 1, pp. 15-39.

[5] Aranda, G.R. (1984). “Ductility demands for R/C frames irregular in elevation”. Proceedings of the Eighth World Conference on Earthquake Engineering, San Francisco, U.S.A., Vol. 4, pp. 559-566.

[6] Shahrooz, B.M., Moehle, J.P. (1990). “Seismic response and design of setback buildings”. Journal of Structural Engineering, ASCE, Vol. 116, No. 5, pp. 1423-1439.

[7] Wood S.L. (1992). “Seismic response of R/C frames with irregular profiles”. Journal of Structural Engineering, Vol. 118, pp. 545-566.

[8] Wong, C.M., Tso, W.K., (1994). “Seismic loading for buildings with setbacks”. Canadian Journal of Civil Engineering, Vol. 21, pp. 863-871.

[9] Magliulo, G., Ramasco, R., Realfonzo, R. (2002). “A critical review of seismic code provisions for vertically irregular frames”. Proceedings of the third European workshop on the seismic behavior of irregular and complex structures, Florence.

[10] Bosco, M., Ghersi, A., Marino, E., Rossi, P.P. (2002). “Effects of in elevation irregularity on the elastic seismic response of in-plan asymmetric buildings”. Proceedings of the third European workshop on the seismic behavior of irregular and complex structures, Florence, Italy.

[11] Das, S., Nau, M. (2003). “Seismic design aspects of vertically irregular reinforced concrete buildings”. Earthquake Spectra, Vol. 19, pp. 455–477.

[12] Colunga, T.A. (2004). “Evaluation of the seismic response of slender, setback RC moment-resisting frame buildings designed according to the seismic guidelines of a modern building code”. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, Canada.

[13] Romão, X., Costa A., Delgado, R. (2004). “Seismic behavior of reinforced concrete frames with setbacks”. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, Canada.

[14] Chintanapakdee, C., Chopra, A.K. (2004). “Evaluation of modal pushover analysis using vertically irregular frames”. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, Canada.

[15] Lee, H.S., Ko, D.W. (2004). “Seismic response of high-rise RC bearing-wall structures with irregularities at bottom stories”. Proceedings of the 13th World Conference on Earthquake Engineering, Vancouver, Canada.

[16] Tremblay, R., Poncet, L. (2005). “Seismic performance of concentrically braced steel frames in multistory buildings with mass irregularity”. Journal of Structural Engineering, Vol. 131, pp. 1363–1375.

[17] Athanassiadou, C., Bervanakis, S. (2005). “Seismic behavior of R/C buildings with setbacks designed to EC8”. Proceedings of the 4th European workshop on the seismic behavior of irregular and complex structures, Thessaloniki, Greece.

[18] Khoury, W., Rutenberg, A., Levy, R. (2005). “On the seismic response of a symmetric setback perimeter-frame structures”. Proceedings of the 4th European workshop on the seismic behavior of irregular and complex structures, Thessaloniki, Greece.

[19] Fragiadakis, M., Vamvatsikos, D., Papadrakakis, M. (2005). “Evaluation of the influence of vertical stiffness irregularities on the seismic response of a 9-story steel frame”. Proceedings of the 4th European workshop on the seismic behavior of irregular and complex structures, Thessaloniki, Greece.

[20] DeStefano, M., Marino, E.M., Viti, S. (2005). “Evaluation of second order effects on the seismic response of vertically irregular RC framed structures”. Proceedings of the 4th European workshop on the seismic behavior of irregular and complex structures, Thessaloniki, Greece.

[21] Lignos, D.G., Gantes, C.J. (2005). “Seismic demands for steel braced frames with stiffness irregularities based on modal pushover analysis”. Proceedings of the 4th European workshop on the seismic behavior of irregular and complex structures, Thessaloniki, Greece.

[22] Reinhorn, A.M., Kusumastuti, D., Rutenberg A. (2005). “Seismic response of irregular frame structures near collapse: experimental and analytical investigation”. Proceedings of the 4th European workshop on the seismic behavior of irregular and complex structures, Thessaloniki, Greece.

[23] Athanassiadou, C.J. (2008). “Seismic performance of R/C plane frames irregular in elevation”. Engineering Structures, Vol. 30, pp. 1250–1261.

[24] Sarkara, P., Prasad, A., Menon, D. (2010). “vertical geometric irregularity in stepped building frames”. Engineering Structures, Vol. 32, pp. 2175-2182.

[25] ONBR, (2009). “National building regulations, part 9: Design and construction of R.C. buildings” Office of National Building Regulations, Tehran, Iran.

[26] BHRC, (2005). “Iranian code of practice for seismic resistant design of buildings, standard No. 2800”. 3rd Revision, Building & Housing Research Center, Tehran, Iran.

[27] PEER, (2013). “Strong ground motion database”. Pacific earthquake engineering research centre (PEER), http://peer.berkeley.edu.

[28] Park, Y.J., Reinhorn, A.M., Kunnath, S.K. (1987). “IDARC: Inelastic damage analysis of reinforced concrete frame - shear-wall structures”. Technical Report NCEER-87-0008, State University of New York at Buffalo.

[29] ODTA, (2005). “Technical Criteria Codification & Earthquake Risk Reduction Affairs Bureau Management and Planning Organization”. The Instruction for Seismic Rehabilitation of Existing Buildings of Iran criteria, No. 360, Office of Deputy for Technical Affairs, Tehran, Iran.