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Simplified procedure for seismic demands assessment of structures

  • Chikh, Benazouz (Earthquake Engineering Division, National Earthquake Engineering Research Center) ;
  • Mehani, Youcef (Earthquake Engineering Division, National Earthquake Engineering Research Center) ;
  • Leblouba, Moussa (Department of Civil & Environmental Engineering, College of Engineering, University of Sharjah)
  • Received : 2015.12.22
  • Accepted : 2016.04.15
  • Published : 2016.08.10

Abstract

Methods for the seismic demands evaluation of structures require iterative procedures. Many studies dealt with the development of different inelastic spectra with the aim to simplify the evaluation of inelastic deformations and performance of structures. Recently, the concept of inelastic spectra has been adopted in the global scheme of the Performance-Based Seismic Design (PBSD) through Capacity-Spectrum Method (CSM). For instance, the Modal Pushover Analysis (MPA) has been proved to provide accurate results for inelastic buildings to a similar degree of accuracy than the Response Spectrum Analysis (RSA) in estimating peak response for elastic buildings. In this paper, a simplified nonlinear procedure for evaluation of the seismic demand of structures is proposed with its applicability to multi-degree-of-freedom (MDOF) systems. The basic concept is to write the equation of motion of (MDOF) system into series of normal modes based on an inelastic modal decomposition in terms of ductility factor. The accuracy of the proposed procedure is verified against the Nonlinear Time History Analysis (NL-THA) results and Uncoupled Modal Response History Analysis (UMRHA) of a 9-story steel building subjected to El-Centro 1940 (N/S) as a first application. The comparison shows that the new theoretical approach is capable to provide accurate peak response with those obtained when using the NL-THA analysis. After that, a simplified nonlinear spectral analysis is proposed and illustrated by examples in order to describe inelastic response spectra and to relate it to the capacity curve (Pushover curve) by a new parameter of control, called normalized yield strength coefficient (${\eta}$). In the second application, the proposed procedure is verified against the NL-THA analysis results of two buildings for 80 selected real ground motions.

Keywords

References

  1. Albanesi, T., Nuti, C. and Vanzi, I. (2000), "A simplified procedure to assess the seismic response of nonlinear structures", Earthq. Spectra, 16(4), 715-734. https://doi.org/10.1193/1.1586136
  2. ATC (1996), Seismic evaluation and retrofit of concrete buildings, Applied Technology Council, California.
  3. 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
  4. Bosco, M., Ghersi, A., Marino, E.M. and Rossi, P.P. (2013), "Comparison of nonlinear static methods for the assessment of asymmetric buildings", Bull. Earthq. Eng., 11(6), 2287-2308. https://doi.org/10.1007/s10518-013-9516-6
  5. Bracci, J.M., Kunnath, S.K. and Reinhorn, A.M. (1997), "Seismic performance and retrofit evaluation for reinforced concrete structures", J. Struc. Eng., ASCE, 123(1), 3-10. https://doi.org/10.1061/(ASCE)0733-9445(1997)123:1(3)
  6. Camara, A. and Astiz, M.A. (2012), "Pushover analysis for the seismic response prediction of cable-stayed bridges under multi-directional excitation", Eng. Struct., 41, 444-455. https://doi.org/10.1016/j.engstruct.2012.03.059
  7. CEN Eurocode 8 (2005), Design of structures for earthquake resistance, Part 3: assessment and retrofitting of buildings, European standard EN 1998-3, European Committee for Standardization, Brussels.
  8. Chikh, B., Leblouba, M., Mehani. Y., Kibboua, A., Hadid, M. and Zerzour, A. (2014), "Ductility spectrum method for design and verification of structures: single-degree-of-freedom bilinear systems", Proceedings of the 15th European Conference on Earthquake Engineering, Istanbul, Turkey, August.
  9. Chopra, A.K. (2007), Dynamics of Structures-Theory and Applications to Earthquake Engineering, 3rd Edition, Prentice Hall, New Jersey.
  10. Chopra, A.K. and Chatpan, C. (2003), "Inelastic deformation ratios for design and evaluation of structures: single-degree-of-freedom bilinear systems", EERC, Berkely, California, September.
  11. Chopra, A.K. and Chatpan, 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)
  12. Chopra, A.K. and Goel, R.K. (1999), "Capacity-demand-diagrams based on inelastic design spectrum", Earthq. Spectra, 15(4), 637-656. https://doi.org/10.1193/1.1586065
  13. Chopra, A.K. and Goel, R.K. (2001), "A modal pushover analysis procedure to estimate seismic demands for buildings: theory and preliminary evaluation", PEER, Berkely, California, March.
  14. Chopra, A.K. and Goel, R.K. (2002), "A modal pushover analysis procedure for estimating seismic demands for buildings", Earthq. Eng. Struct. D., 31(3), 561-582. https://doi.org/10.1002/eqe.144
  15. Fajfar, P. (1999), "Capacity spectrum method based on inelastic demand spectra", Earthq. Eng. Struct. D., 28(9), 979-993. https://doi.org/10.1002/(SICI)1096-9845(199909)28:9<979::AID-EQE850>3.0.CO;2-1
  16. Fajfar, P. and Fischinger, M. (1988), "N2 a method for nonlinear seismic analysis of regular structures", Proceedings of 9th World Conference on Earthquake Engineering, Tokyo-Kyoto, Japan, 5, 111-116.
  17. Freeman, S.A., Nicoletti, J.P. and Tyrell, J.V. (1975), "Evaluation of existing buildings for seismic risk-a case study of Puget Sound Naval Shipyard", Proceedings of 1st U S National Conference on Earthquake Engineering, Berkeley, USA.
  18. Fujii, K. (2013), "Prediction of the largest peak nonlinear seismic response of asymmetric buildings under bi-directional excitation using pushover analyses", Bull. Earthq. Eng., 12(2), 909-938. https://doi.org/10.1007/s10518-013-9557-x
  19. Gulkan, P. and Sozen, M. (1974), "Inelastic response of reinforced concrete structures to earthquake motions". ACI J Pr., 71(12), 604-610.
  20. Gupta, B. and Kunnath, S.K. (2000), "Adaptive spectra-based pushover procedure for seismic evaluation of structures", Earthq. Spectra, 16(2), 367-392. https://doi.org/10.1193/1.1586117
  21. Jan, T.S., Liu, M.W. and Kao, Y.C. (2004), "An upper-bound pushover analysis procedure for estimating the seismic demands of high-rise buildings", Eng. Struct., 26(1), 117-128. https://doi.org/10.1016/j.engstruct.2003.09.003
  22. Kaatsiz, K. and Sucuoglu, H. (2014), "Generalized force vectors for multi-mode pushover analysis of torsionally coupled systems", Earthq. Eng. Struct. D., 43(13), 2015-2033. https://doi.org/10.1002/eqe.2434
  23. 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
  24. Kowalsky, M.J. (1994), "Displacement-based design-a methodology for seismic design applied to RC bridge columns", Master's Thesis, University of California at San Diego, La Jolla, California.
  25. Lin, J.L. and Tsai, K.C. (2011), "Estimation of the seismic energy demands of two-way asymmetric-plan building systems", Bull. Earthq. Eng., 9(2), 603-621. https://doi.org/10.1007/s10518-010-9214-6
  26. Lin, Y.Y. and Chang, K.C. (2003), "An improved capacity spectrum method for ATC-40", Earthq. Eng. Struct. D., 32(13), 2013-2025. https://doi.org/10.1002/eqe.312
  27. Maja, K. and Fajfar, P. (2012), "The extended N2 method considering higher mode effects in both plan and elevation", Bull. Earthq. Eng., 10(2), 695-715. https://doi.org/10.1007/s10518-011-9319-6
  28. Manoukas, G. and Avramidis, I. (2014), "Evaluation of a multimode pushover procedure for asymmetric in plan buildings under biaxial seismic excitation", Bull. Earthq. Eng., 12(6), 2607-2632. https://doi.org/10.1007/s10518-014-9600-6
  29. Matsumori, T., Otani, S., Shiohara, H. and Kabeyasawa, T. (1999), "Earthquake member deformation demands in reinforced concrete frame structures", Proceeding U.S.-Japan Workshop on Performance-Based Earthq. Engrg. Methodology for R/C Bldg. Structures, Maui, Hawaii
  30. Miranda, E. (2001) "Estimation of inelastic deformation demands of SDOF systems", J. Struct. Eng., 127(9), 1005-1012. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:9(1005)
  31. Newmark, N.M. and Hall, W.J. (1982), "Earthquake spectra and design", Earthquake Engineering Research Institute, Berkeley, California.
  32. Paret, T.F., Sasaki, K.K., Eilbekc, D.H. and Freeman, S.A. (1996), "Approximate inelastic procedures to identify failure mechanisms from higher mode effects", Proceeding of the 11th World Conference Earthq. Eng., Paper No. 966, Acapulco, Mexico.
  33. PEER Strong Motion Database, http://peer.berkeley.edu/smcat.
  34. Poursha, M., Khoshnoudian, F. and Moghadam, A.S. (2009), "A consecutive modal pushover procedure for estimating the seismic demands of tall buildings", Eng. Struct., 31(2), 591-599. https://doi.org/10.1016/j.engstruct.2008.10.009
  35. Priestley, M.J. and Kowalsky, M.J. (2000), "Direct Displacement-Based Seismic Design of Concrete Buildings", Bull N.Z. Soc. Earthq. Eng., 33(4), 421-444.
  36. Reinhorn, A.M. (1997), "Inelastic analysis techniques in seismic evaluations", Eds. Fajfar, P. and Krawinkler, H., "Seismic design methodologies for the next generation of codes", Balkema, Rotterdam, 277-287.
  37. Reinhorn, A.M., Valles, R.E. and Kunnath, S.K. (2006), IDARC 2D version 6.1-User's Guide, State University of New York, Buffalo, NY.
  38. Reyes, J.C. and Chopra, A.K. (2011), "Three-dimensional modal pushover analysis of buildings subjected to two components of ground motion, including its evaluation for tall buildings", Earthq. Eng. Struct. D., 40(7), 789-806. https://doi.org/10.1002/eqe.1060
  39. RPA (2003), Algerian seismic building code, National Center of Applied Research in Earthquake Engineering CGS, Algiers.
  40. Sasaki, K.K., Freeman, S.A. and Paret, T.F. (1998), "Multimode pushover procedure (MMP)-A method to identify the effects of higher modes in a pushover analysis", Proceeding of the 6th U.S. National Conference on Earthquake Engineering, Seattle, Washington.
  41. Timothy, G.S.E., Newell, J. and Sinclair, M. (2014), "Use of the extended consecutive modal pushover analysis method to optimize the design process", Bridges Structures Congress 2012, 1709-1720.
  42. Wen, Y.K. (1976), "Method for random vibration of hysteretic systems", J. Eng. Mech., 102(2), 249-263.
  43. 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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