Earthquakes and Structures

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Seismic structural demands and inelastic deformation ratios: Sensitivity analysis and simplified models

  • Chikh, Benazouz (National Earthquake Engineering Research Center, CGS) ;
  • Laouami, Nacer (National Earthquake Engineering Research Center, CGS) ;
  • Mebarki, Ahmed (University Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle (MSME)) ;
  • Leblouba, Moussa (Department of Civil & Environmental Engineering, College of Engineering, University of Sharjah) ;
  • Mehani, Youcef (National Earthquake Engineering Research Center, CGS) ;
  • Kibboua, Abderrahmane (National Earthquake Engineering Research Center, CGS) ;
  • Hadid, Mohamed (National School of Built and Ground Works Engineering (ENSTP)) ;
  • Benouar, Djillali (University of Science & Technology HouariBoumediene (USTHB), Faculty of Civil Engineering)
  • Received : 2016.05.04
  • Accepted : 2017.07.03
  • Published : 2017.07.25
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Abstract

Modern seismic codes rely on performance-based seismic design methodology which requires that the structures withstand inelastic deformation. Many studies have focused on the inelastic deformation ratio evaluation (ratio between the inelastic and elastic maximum lateral displacement demands) for various inelastic spectra. This paper investigates the inelastic response spectra through the ductility demand ${\mu}$, the yield strength reduction factor $R_y$, and the inelastic deformation ratio. They depend on the vibration period T, the post-to-preyield stiffness ratio ${\alpha}$, the peak ground acceleration (PGA), and the normalized yield strength coefficient ${\eta}$ (ratio of yield strength coefficient divided by the PGA). A new inelastic deformation ratio $C_{\eta}$ is defined; it is related to the capacity curve (pushover curve) through the coefficient (${\eta}$) and the ratio (${\alpha}$) that are used as control parameters. A set of 140 real ground motions is selected. The structures are bilinear inelastic single degree of freedom systems (SDOF). The sensitivity of the resulting inelastic deformation ratio mean values is discussed for different levels of normalized yield strength coefficient. The influence of vibration period T, post-to-preyield stiffness ratio ${\alpha}$, normalized yield strength coefficient ${\eta}$, earthquake magnitude, ruptures distance (i.e., to fault rupture) and site conditions is also investigated. A regression analysis leads to simplified expressions of this inelastic deformation ratio. These simplified equations estimate the inelastic deformation ratio for structures, which is a key parameter for design or evaluation. The results show that, for a given level of normalized yield strength coefficient, these inelastic displacement ratios become non sensitive to none of the rupture distance, the earthquake magnitude or the site class. Furthermore, they show that the post-to-preyield stiffness has a negligible effect on the inelastic deformation ratio if the normalized yield strength coefficient is greater than unity.

Keywords

Acknowledgement

Supported by : National Earthquake Engineering Research Center (CGS, Algeria)

References

  1. Akkar, S. and Miranda, E. (2004), "Improved displacement modification factor to estimate maximum deformations of short period structures", 13th World Conference on Earthquake Engineering.
  2. ATC-40. (1996), "Seismic evaluation and retrofit of concrete buildings", Applied Technology Council, report ATC-40. Redwood City.
  3. Baez, J.I. and Miranda, E. (2000), "Amplification factors to estimate inelastic displacement demands for the design of structures in the near field", Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand, January.
  4. Benazouz, C., Moussa, L. and Ali, Z. (2012), "Ductility and inelastic deformation demands of structures", Struct. Eng. Mech., 42(5), 631-644. https://doi.org/10.12989/sem.2012.42.5.631
  5. Chikh, B., Mebarki, A., Laouami, N., Leblouba, M., Mehani, Y., Hadid, M., Kibboua, A. and Bennouar, D. (2017), "Seismic structural demands and inelastic deformation ratios: a theoretical approach", Earthq. Struct., 12(4), 397-407. https://doi.org/10.12989/eas.2017.12.4.397
  6. Chopra, A.K. and Chiatanapakdee, C. (2003), "Inelastic deformation ratios for design and evaluation of structures.Rep. No.EERC-2003-09, EERC, Univ. of California at Berkeley, Berkeley, California.
  7. Chopra, A.K. and Chintanapakdee, C. (2004), "Inelastic deformation ratios for design and evaluation of structures: single-degree-of-freedom bilinear systems", J. Struct. Eng., 130(9), 1309-1319. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:9(1309)
  8. Datafit version 9.0.59, Curve fitting software, Oakdale Engineering, PA, USA.
  9. FEMA. (2005), "Improvement of nonlinear static seismic analysis procedures", FEMA-440, Redwood City.
  10. Federal Emergency Management Agency (1997), "NEHRP guidelines for the seismic rehabilitation of buildings", Rept. FEMA 273 (Guidelines) and Rept. 274 (Commentary), Washington, D.C.
  11. Hatzigeorgiou, G.D. and Beskos, D.E. (2009), "Inelastic displacement ratios for SDOF structures subjected to repeated earthquakes", Eng. Struct., 31(11), 2744-2755. https://doi.org/10.1016/j.engstruct.2009.07.002
  12. Kazaz, L. (2016), "Seismic deformation demands on rectangular structural walls in frame-wall systems", Earthq. Struct., 10(2), 329-350. https://doi.org/10.12989/eas.2016.10.2.329
  13. Krawinkler, H. and Nassar, A.A. (1992), "Seismic design based on ductility and cumulative damage demands and capacities", Nonlinear seismic analysis and design of reinforced concrete buildings, 23-39.
  14. Mahin, S.A. and Lin, J. (1983), "Construction of inelastic response spectra for single-degree-of-freedom systems", Computer program and applications, Report No. UCB/EERC-83/17, University of California, Berkeley.
  15. Malaga, C. and Elghazouli, A.Y. (2012), "Inelastic displacement demands in steel structures and their relationship with earthquake frequency content parameters", Earthq. Eng. Struct. Dyn., 41(5), 831-852. https://doi.org/10.1002/eqe.1156
  16. Matamoros, A., Browning, J. and Luft, M. (2003), "Evaluation of simple methods for estimating drift of reinforced concrete buildings subjected to earthquakes", Earthq. Spectra, 19(4), 839-861. https://doi.org/10.1193/1.1623781
  17. Massumi, A. and Monavari, B. (2013), "Energy based procedure to obtain target displacement of reinforced concrete structures", Earthq. Struct., 48(5), 681-695.
  18. Mehanny, S.S.F. (2008), "Variability in inelastic displacement demands: Uncertainty in system parameters versus randomness in ground records", Eng. Struct., 30(4), 1002-1013. https://doi.org/10.1016/j.engstruct.2007.06.009
  19. Miranda, E. (1991), "Seismic evaluation and upgrading of existing structures", Ph.D. thesis, Univ. of California at Berkeley, Berkeley, California.
  20. Miranda, E. (1993), "Evaluation of site-dependent inelastic seismic design spectra", J. Struct. Eng., 119(5), 1319-1338. https://doi.org/10.1061/(ASCE)0733-9445(1993)119:5(1319)
  21. Miranda, E. (2000), "Inelastic displacement ratios for structures on firm sites", J. Struct. Eng., 126(10), 1150-1159. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:10(1150)
  22. Miranda, E. and Ruiz-Garcia, J. (2002), "Evaluation of approximate methods to estimate maximum inelastic displacement demands", Earthq. Eng. Struct. D., 31(3), 539-560. https://doi.org/10.1002/eqe.143
  23. Newmark, N.M. and Hall, W.J. (1982), "Earthquake spectra and design", Earth Syst. Dyn., 1.
  24. PEER Strong Motion Database (2011), http://peer.berkeley.edu/smcat.
  25. Ruiz-Garcia, J. and Miranda, E, (2003), "Inelastic displacement ratios for evaluation of existing structures", Earthq. Eng. Struct. D., 32(8), 1237-1258. https://doi.org/10.1002/eqe.271
  26. Ruiz-Garcia, J. and Miranda, E. (2004), "Inelastic displacement ratios for design of structures on soft soils sites", J. Struct. Eng., 130(12), 2051-2061. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:12(2051)
  27. Ruiz-Garcia, J. and Miranda, E. (2006), "Inelastic displacement ratios for evaluation of structures built on soft soil sites", Earthq. Eng. Struct. D., 35(6), 679-694. https://doi.org/10.1002/eqe.552
  28. Ruiz-Garcia, J. and Gonzalez, E.J. (2014), "Implementation of displacement coefficient method for seismic assessment of buildings built on soft soil sites", Eng. Struct., 59, 1-12. https://doi.org/10.1016/j.engstruct.2013.10.017
  29. Sang, W.H., Sung, J.H., Ki, H.M. and Myoungsu, S. (2014), "Improved capacity spectrum method with inelastic displacement ratio considering higher mode effects", Earthq. Struct., 7(4), 587-607. https://doi.org/10.12989/eas.2014.7.4.587
  30. Skrekas, P., Sextos, A. and Giaralis, A. (2014), "Influence of bidirectional seismic pounding on the inelastic demand distribution of three adjacent multi-storey R/C buildings", Earthq. Struct., 6(1), 71-87. https://doi.org/10.12989/eas.2014.6.1.071
  31. Wen, Y.K. (1976), "Method for random vibration of hysteretic systems", J. Eng. Mech., 102(2), 249-263.
  32. Whittaker, A., Constantinou, M. and Tsopelas, P. (1998), "Displacement estimates for performance-based seismic design", J. Struct. Eng., 124(8), 905-912. https://doi.org/10.1061/(ASCE)0733-9445(1998)124:8(905)
  33. Zhai, C., Wen, W.P., Zhu, T.T. and Lis, Xiel (2013), "Inelastic displacement ratios for design of structures with constant damage performance", Eng. Struct., 52, 53-63. https://doi.org/10.1016/j.engstruct.2013.02.008
  34. Zhai, C., Lis, Xiel and Sun, Y. (2007), "Study on inelastic displacement ratio spectra for near-fault pulse-type ground motions", Earthq. Eng. Eng. Vibr., 6(4), 351-355. https://doi.org/10.1007/s11803-007-0755-x
  35. Yazdani, A. and Salimi, M.R. (2015), "Earthquake response spectra estimation of bilinear hysteretic systems using randomvibration theory method", Earthq. Struct., 8(5), 1055-1067. https://doi.org/10.12989/eas.2015.8.5.1055
  36. Zerbin, M. and Aprile, A. (2015), "Sustainable retrofit design of RC frames evaluated for different seismic demand", Earthq. Struct., 9(6), 1337-1353. https://doi.org/10.12989/eas.2015.9.6.1337

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