Abstract
Floor response spectra, which are used for the seismic design of equipment, are often based on the assumption that the behaviour of a structure and its equipment is linearly elastic. Significant reductions in the peak values of floor acceleration spectra can be achieved if inelastic behaviour of the structure is taken into account. This paper presents the most important results of an extensive parametric study of floor acceleration spectra, taking into account inelastic behaviour of the structure, and linear elastic behaviour of the equipment. The structure and the equipment were modelled as single-degree-of-freedom systems. The influences of the input ground motion, ductility, hysteretic behaviour and the natural period of the structure, as well as that of damping of the equipment, have been studied. A simple practice-oriented method for direct determination of floor acceleration spectra from an inelastic spectrum for the structure and an elastic spectrum for the equipment is proposed and validated. In this method, the floor response spectra in the resonance region, where the natural period of the equipment is close to the natural period of the structure, are based on the empirical values obtained in the parametric study, whereas the spectra in the pre- and post-resonance regions are based on the principles of dynamics of structures. The method is intended for a quick estimation of approximate floor acceleration spectra.
Similar content being viewed by others
References
Adam C, Fotiu PA (2000) Dynamic analysis of inelastic primary-secondary systems. Eng Struct 22(1):58–71. doi:10.1016/S0141-0296(98)00073-X
Adam C, Furtmüller T (2008) Response of nonstructural components in ductile load-bearing structures subjected to ordinary ground motions. In: Proceedings of the 14th world conference on earthquake engineering, Paper no 05-01-0327, Beijing, China, 12–17 October 2008
Adam C, Furtmüller T, Moschen L (2013) Floor response spectra for moderately heavy nonstructural elements attached to ductile frame structures. Comput Method Earthq Eng 2:69–89. doi:10.1007/978-94-007-6573-3_4
Akiyama H (1985) Earthquake-resistant limit-state design for buildings. University of Tokyo Press, Tokyo
ASCE 4-98 (2000) Seismic analysis of safety-related nuclear structures and commentary. American Society of Civil Engineers, Reston, VA
CEN (2004) Eurocode 8—design of structures for earthquake resistance. Part 1: general rules, seismic actions and rules for buildings. European standard EN 1998-1. European Committee for Standardization, Brussels
Chaudhuri SR, Villaverde R (2008) Effect of building nonlinearity on seismic response of nonstructural components: a parametric study. ASCE J Struct Eng 134(4):661–670. doi:10.1061/(ASCE)0733-9445(2008)134:4(661)
Fajfar P, Novak D (1995) Floor response spectra for inelastic structures. In: Transactions of the 13th international conference on structural mechanics in reactor technology (SMiRT 13), Paper no K044/1:259–264, Porto Alegre, Brazil, 13–18 August 1995
Iervolino I, Galasso C, Cosenza E (2010) REXEL: computer aided record selection for code-based seismic structural analysis. Bull Earthq Eng 8(2):339–362. doi:10.1007/s10518-009-9146-1
Igusa T (1990) Response characteristics of inelastic 2-DOF primary-secondary system. ASCE J Eng Mech 116(5):1160–1174. doi:10.1061/(ASCE)0733-9399(1990)116:5(1160)
Jayaram N, Lin T, Baker JW (2011) A computationally efficient ground-motion selection algorithm for matching a target response spectrum mean and variance. Earthq Spectra 27(3):797–815. doi:10.1193/1.3608002
Lin J, Mahin SA (1985) Seismic response of light subsystems on inelastic structures. ASCE J Struct Eng 111(2):400–417. doi:10.1061/(ASCE)0733-9445(1985)111:2(400)
Medina RA, Sankaranarayanan R, Kingston KM (2006) Floor response spectra for light components mounted on regular moment-resisting frame structures. Eng Struct 28(14):1927–1940. doi:10.1016/j.engstruct.2006.03.022
Miranda E, Bertero V (1994) Evaluation of strength reduction factors for earthquake-resistant design. Earthq Spectra 10(2):357–379. doi:10.1193/1.1585778
Novak D, Fajfar P (1994) Nelinearni etažni spektri odziva za racionalno aseizmično projektiranje opreme. In: Zbornik 16. zborovanja gradbenih konstruktorjev Slovenije. Bled, Slovenia, 8–9 September 1994, pp 95–102 (in Slovenian)
Oropeza M, Favez P, Lestuzzi P (2010) Seismic response of nonstructural components in case of nonlinear structures based on floor response spectra method. Bull Earthq Eng 8(2):387–400. doi:10.1007/s10518-009-9139-0
Politopoulos I (2010) Floor spectra of nonlinear MDOF structures. J Earthq Eng 14(5):726–742. doi:10.1080/13632460903427826
Politopoulos I, Feau C (2007) Some aspects of floor spectra of 1DOF nonlinear primary structures. Earthq Eng Struct Dyn 36(8):975–993. doi:10.1002/eqe.664
Rodriguez ME, Restrepo JI, Carr AJ (2002) Earthquake-induced floor horizontal accelerations in buildings. Earthq Eng Struct Dyn 31(3):693–718. doi:10.1002/eqe.149
Saiidi M, Sozen MA (1979) Simple and complex models for nonlinear seismic response of reinforced concrete structures. Civil Engineering Studies, Structural Research Series No. 465. University of Illinois, Urbana, IL
Sankaranarayanan R, Medina RA (2007) Acceleration response modification factors for nonstructural components attached to inelastic moment-resisting frame structures. Earthq Eng Struct Dyn 36(14):2189–2210. doi:10.1002/eqe.724
Sewell RT, Cornell CA, Toro GR, McGuire RK (1986) A study of factors influencing floor response spectra in nonlinear multi-degree-of-freedom-structures, Report No. 82. The John A. Blume Earthquake Engineering Center, Stanford University, Stanford, CA
Shooshtari M, Saatcioglu M, Naumoski N, Foo S (2010) Floor response spectra for seismic design of operational and functional components of concrete buildings in Canada. Can J Civ Eng 37(12):1590–1599. doi:10.1139/L10-094
Singh MP, Chang T-S, Suarez LE (1996) Floor response spectrum amplification due to yielding of supporting structure. In: Proceedings of the 11th world conference on earthquake engineering, Paper no 1444, Acapulco, Mexico, 23–28 June 1996
Sullivan TJ, Calvi PM, Nascimbene R (2013) Towards improved floor spectra estimates for seismic design. Earthq Struct 4(1):109–132
USNRC (1978) Regulatory Guide 1.122. Development of floor design response spectra for seismic design of floor-supported equipment or components, Revision 1. U.S. Nuclear Regulatory Commission, Washington, DC
Vidic T, Fajfar P, Fischinger M (1994) Consistent inelastic design spectra: strength and displacement. Earthq Eng Struct Dyn 23(5):507–521. doi:10.1002/eqe.4290230504
Villaverde R (1987) Simplified approach for the seismic analysis of equipment attached to elastoplastic structures. Nucl Eng Des 103(3):267–279. doi:10.1016/0029-5493(87)90310-4
Villaverde R (1997) Seismic design of secondary structures: state of the art. ASCE J Struct Eng 123(8):1011–1019. doi:10.1061/(ASCE)0733-9445(1997)123:8(1011)
Villaverde R (2006) Simple method to estimate the seismic nonlinear response of nonstructural components in buildings. Eng Struct 28(8):1209–1221. doi:10.1016/j.engstruct.2005.11.016
Vukobratović V, Fajfar P (2012) A method for direct determination of inelastic floor response spectra. In: Proceedings of the 15th World conference on earthquake engineering, Paper no 727, Lisbon, Portugal, 24–28 September 2012
Vukobratović V, Fajfar P (2013) A method for direct generation of floor acceleration spectra for inelastic structures. In: Transactions of the 22nd international conference on structural mechanics in reactor technology (SMiRT 22), Paper no 215, San Francisco, USA, 18–23 August 2013
Yasui Y, Yoshihara J, Takeda T, Miyamoto A (1993) Direct generation method for floor response spectra. In: Transactions of the 12th international conference on structural mechanics in reactor technology (SMiRT 12), Paper no K13/4:367–372, Stuttgart, Germany, 15–20 August 1993
Acknowledgments
The work of the first author was partially funded by the Serbian Ministry of Science and Technology, Grant No. 36043. The work of the second author was financially supported by the Slovenian Research Agency, project J2-4180.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Vukobratović, V., Fajfar, P. A method for the direct determination of approximate floor response spectra for SDOF inelastic structures. Bull Earthquake Eng 13, 1405–1424 (2015). https://doi.org/10.1007/s10518-014-9667-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10518-014-9667-0