An Alternative Recommendation for Design Eccentricity

Year 2023, Volume: 26 Issue: 2, 609 - 623, 05.07.2023

Osman Akyürek

https://doi.org/10.2339/politeknik.979143

Cited By: 1

Abstract

In this study, a new recommendation for the design eccentricity is proposed. One-story; three-story; and five-story elastic systems with all the same slab, column, beam sizes, and their orientations in the plane were investigated according to the Turkish Earthquake Building Code (TEBC-2018) by Response Spectrum Analysis (RSA). The obtained results are compared with the TEBC-2018 design parameters. The results showed accidental eccentricity is proportional to torsional stiffness and rotational response. If the rotational response increases, it leads to an increase in accidental eccentricity instead of translational stiffness and response in the direction where the earthquake strikes the structure. In addition, the proposed method was approximately the same as RSA for a single-story building by considering the effect of the accidental eccentricity. At the same time, it was found to be approximately 12-15% less for three- and five-story buildings. However, it was revealed from the results that the proposed method was more successful in estimating the additional (accidental) eccentricity effect than the current earthquake code.

Keywords

Torsional irregularity, accidental eccentricity, center of mass (CM), center of rigidity (CR), Turkish Earthquake Building Code (TEBC).

Tasarım Eksantrikliği İçin Alternatif Bir Öneri

Abstract

Bu çalışmada, burulma düzensizliğini yeniden dikkate almak için frekans oranı ve etkili dönme yarıçapı tanımını içeren alternatif tasarım eksantriklik formülü önerilmiştir. Bu amaçla, aynı kat planı ve yapı elemanlarına sahip bir, üç ve beş katlı binaların iki yönlü burulma etkisi altında deprem yer hareketinin çift yönlü spektrum analizleri yapılarak yukarıda adı geçen binalar Türkiye Bina Deprem Yönetmeliği (TBDY-2018) tasarımına göre incelenmiştir. Bu çerçevede, elde edilen sonuçlar, TBDY-2018 tasarım parametreleri ile karşılaştırılmıştır. Karşılaştırılan sonuçlara göre, ek dışmerkezliğin her bir kattaki burulma rijitliği ve dönme ile doğru orantılı olduğu saptanmıştır. Bir başka deyişle, yapının plandaki burulma etkisinin çoğalması depremin yapıya etkidiği yöndeki ek dışmerkezlikte bir artışa neden olmuştur. Ayrıca, önerilen yönteme göre ek dışmerkezlik etkisi tek katlı bina için spektrum analiz sonucuyla neredeyse aynıyken bu durum üç ve beş katlı binalarda ise yaklaşık olarak %12-%15 arasında daha az bulunmuştur. Sonuç olarak önerilen yöntem ek dışmerkezlik etkisini tahmin etmede mevcut yönetmeliğe göre daha başarılı olduğu görülmüştür.

Keywords

Burulma düzensizliği, ek dışmerkezlik, kütle merkezi (KM), rijitlik merkezi (RM), deprem yönetmeliği TBDY-2018

References

• [1] O. Akyürek, “Lateral and Torsional Seismic Vibration Control for Torsionally Irregular Buildings,” Florida Institute of Technology, (2019).
• [2] A. M. Chandler and G. L. Hutchinson, “Torsional coupling effects in the earthquake response of asymmetric buildings,” Eng. Struct., 8( 4): 222–236, (1986).
• [3] FEMA 750, “NEHRP (National Earthquake Hazards Reduction Program) Recommended Seismic Provisions for New Buildings and Other Structures (FEMA P-750), 2009 Edition,” (2009).
• [4] D. S. Moon, “Integrated Seismic Assessment and Design Of Plan-Irregular Structures,” University of Illinois at Urbana-Champaign, (2012).
• [5] A. R. and G. T. Francisco Crisafulli, “Consideration of Torsional Effects in the displacement control of ductile buildings,” 13th World Conference on Earthquake Engineering, (2004).
• [6] H. Hao and J. Ip, “Torsional Responses of Building Structures to Earthquake Loadings Defined in AS1170.4-2007,” in Australian Earthquake Engineering Society 2013 Conference, Tasmania, (2013).
• [7] C. L. Kan and A. K. Chopra, “Elastic earthquake analysis of torsionally coupled multistorey buildings,” Earthq. Eng. Struct. Dyn., 5(4): 395–412, (1977).
• [8] W. K. Tso and K. M. Dempsey, “Seismic torsional provisions for dynamic eccentricity,” Earthq. Eng. Struct. Dyn., 8(3): 275–289, (1980).
• [9] R. Hejal and A. K. Chopra, “Earthquake Response of Torsionally Coupled, Frame Buildings,” (1989).
• [10] R. K. Goel and A. K. Chopra, “Dual‐Level Approach for Seismic Design of Asymmetric‐Plan Buildings,” J. Struct. Eng., 120(1): 161–179, (1994).
• [11] M. De Stefano and B. Pintucchi, “A review of research on seismic behaviour of irregular building structures since 2002,” Bull. Earthq. Eng., 6(2): 285–308, (2008).
• [12] J. Hernández and O. López, “Influence of Bidirectional Seismic Motion On the Response of Asymmetric Buildings,” (2000).
• [13] A. Ghersi and P. P. Rossi, “Influence of bi-directional ground motions on the inelastic response of one-storey in-plan irregular systems,” Eng. Struct., 23(6): 579–591, (2001).
• [14] E. Heredia-Zavoni and R. Machicao-Barrionuevo, “Response to orthogonal components of ground motion and assessment of percentage combination rules,” Earthq. Eng. Struct. Dyn., 33(2): 271–284, (2004).
• [15] P. Fajfar, D. Marušić, and I. Peruš, “Torsional effects in the pushover-based seismic analysis of buildings,” J. Earthq. Eng., 9(6): 831–854, (2005).
• [16] G. Magliulo and R. Ramasco, “Seismic response of three-dimensional r/c multi-storey frame building under uni- and bi-directional input ground motion,” Earthq. Eng. Struct. Dyn., 36(12): 1641–1657, (2007).
• [17] G. P. Cimellaro, T. Giovine, and D. Lopez-Garcia, “Bidirectional pushover analysis of irregular structures,” J. Struct. Eng., 140 (9), (2014).
• [18] S. H. Jeong and A. S. Elnashai, “Analytical assessment of an irregular RC frame for full-scale 3D pseudo-dynamic testing part I: Analytical model verification,” Journal of Earthquake Engineering, 9(1): 95–128, (2005).
• [19] J. De-la-Colina, Q. Acuña, A. Hernández, and J. Valdés, “Laboratory tests of steel simple torsionally unbalanced models,” Earthq. Eng. Struct. Dyn., 36(7): 887–907, (2007).
• [20] F. Crisafulli, A. Reboredo, and G. Torrisi, “Consideration of torsional effects in the displacement control of ductile buildings,” 13th World Conference on Earthquake Engineering, (2004).
• [21] D. Basu, M. C. Constantinou, and A. S. Whittaker, “An equivalent accidental eccentricity to account for the effects of torsional ground motion on structures,” Eng. Struct., 69(1): 1–11, (2014).
• [22] G. Özmen, K. Girgin, and Y. Durgun, “Torsional irregularity in multi-story structures,” Int. J. Adv. Struct. Eng., 6(4): 121–131, (2014).
• [23] D. Basu and S. Giri, “Accidental eccentricity in multistory buildings due to torsional ground motion,” Bull. Earthq. Eng., 13(12): 3779– 3808, (2015).
• [24] Y. Cao, G. P. Mavroeidis, K. C. Meza-Fajardo, and A. S. Papageorgiou, “Accidental eccentricity in symmetric buildings due to wave passage effects arising from near-fault pulse-like ground motions,” Earthq. Eng. Struct. Dyn., 46(13): 2185–2207, (2017).
• [25] R. Tabatabaei, “Torsional Vibration of Eccentric Building Systems,” Recent Adv. Vib. Anal., (2011).
• [26] L. Huo and H. Li, “Torsionally coupled response control of structures using,” in The 13th World Conference on Earthquake Engineering, (2017)
• [27] G. Özmen, K. Girgin, and Y. Durgun, “Torsional irregularity in multi-story structures,” Int. J. Adv. Struct. Eng., 6(4): 121–131, (2014).
• [28] AFAD ve Acil Durum Yönetimi Başkanlığı, “Türkiye Bi̇na Deprem Yönetmeli̇ği̇,” (2018).
• [29] Computers and Structures Inc., “SAP2000 Integrated Software for Structural Analysis and Design.” Berkeley, California,USA, (2020).
• [30] J. Raoul, G. Sedlacek, G. Tsionis, J. Raoul, G. Sedlacek, and G. Tsionis, “Eurocode 8 : Seismic Design of Buildings Worked examples. ” (2012).
• [31] American Society of Civil Engineers, “Minimum design loads for buildings and other structures,” ASCE 7-10, no. 7 98. American Society of Civil Engineers, Reston, VA, (Oct., 2000).
• [32] N. Özhendekci and Z. Polat, “Torsional irregularity of buildings,” the 14th World Conference on Earthquake Engineering, (2008).
• [33] H. Gokdemir, H. Ozbasaran, M. Dogan, E. Unluoglu, and U. Albayrak, “Effects of torsional irregularity to structures during earthquakes,” Eng. Fail. Anal., 35(1): 713–717, (2013).