DOI QR코드

DOI QR Code

Equivalent linear and bounding analyses of bilinear hysteretic isolation systems

  • Wang, Shiang-Jung (Department of Civil and Construction Engineering, National Taiwan University of Science and Technology) ;
  • Lee, Hsueh-Wen (Department of Civil and Construction Engineering, National Taiwan University of Science and Technology) ;
  • Yu, Chung-Han (National Center for Research on Earthquake Engineering) ;
  • Yang, Cho-Yen (National Center for Research on Earthquake Engineering) ;
  • Lin, Wang-Chuen (National Center for Research on Earthquake Engineering)
  • Received : 2020.09.07
  • Accepted : 2020.11.11
  • Published : 2020.11.25

Abstract

With verifications through many relevant researches in the past few decades, adopting the equivalent lateral force procedure for designing seismically isolated structures as a preliminary or even final design approach has become considerably mature and publicly acceptable, especially for seismic isolation systems that mechanically exhibit bilinear hysteretic behavior. During the design procedure, in addition to a given seismic demand, structural designers still need to previously determine three parameters, such as mechanical properties of seismic isolation systems or design parameters and performance indices of seismically isolated structures. However, an arbitrary or improper selection of given parameters might cause diverse or even unacceptable design results, thus troubling structural designers very much. In this study, first, based on the criterion that at least either two design parameters or two performance indices of seismically isolated structures are decided previously, the rationality and applicability of design results obtained from different conditions are examined. Moreover, to consider variations of design parameters of seismically isolated structures attributed to uncertainties of mechanical properties of seismic isolation systems, one of the conditions is adopted to perform bounding analysis for seismic isolation design. The analysis results indicate that with a reasonable equivalent damping ratio designed, considering a specific variation for two design parameters (the effective stiffness and equivalent damping ratio) could present more conservative bounding design results (in terms of isolation displacement and acceleration transmissibility) than considering the same variation but for two mechanical properties (the characteristic strength and post-yield stiffness).

Keywords

Acknowledgement

The study was financially aided by the Ministry of Science and Technology (MOST) of Taiwan [108-2221-E-011-005-] and the Architecture and Building Research Institute (ABRI) of Taiwan [108AW761]. The support is greatly acknowledged.

References

  1. ASCE/SEI 7-10 (2010), Minimum design loads for buildings and other structures, American Society of Civil Engineers (ASCE), Reston, V.A.
  2. ASCE/SEI 7-16 (2017), Minimum design loads and associated criteria for buildings and other structures, , American Society of Civil Engineers (ASCE), Reston, V.A.
  3. Calvi, G.M. and Pavese, A. (1997), "Conceptual design of isolation systems for bridge structures", J. Earthq. Eng., 1(1), 193-218. https://doi.org/10.1080/13632469708962366.
  4. Constantinou, M.C., Tsopelas, P., Kasalanati, A. and Wolff, E.D. (1999), "Property modification factors for seismic isolation bearings", Report No. MCEER-99-0012, Multidisciplinary Center for Earthquake Engineering Research, State University of New York, Buffalo, U.S.A.
  5. Constantinou, M.C., Whittaker, A.S., Kalpakidis, Y., Fenz, D.M. and Warn, G.P. (2007), "Performance of seismic isolation hardware under service and seismic loading", Report No. MCEER-07-0012, Multidisciplinary Center for Earthquake Engineering Research, State University of New York, Buffalo, U.S.A.
  6. Deringol, A.H. and Bilgin, H, (2018), "Effects of the isolation parameters on the seismic response of steel frames", Earthq. Struct., 15(3), 319-334. http://dx.doi.org/10.12989/eas.2018.15.3.319.
  7. Hwang, J.S. and Chiou, J.M. (1996), "An equivalent linear model of lead-rubber seismic isolation bearings", Eng. Struct., 18(7), 528-536. https://doi.org/10.1016/0141-0296(95)00132-8.
  8. Hwang, J.S., Chiou, J.M., Sheng, L.H. snd Gates, J.H. (1996), "A refined model for base-isolated bridges with bi-linear hysteresis bearings", Earthq. Spectra, 12(2), 245-274. https://doi.org/10.1193/1.1585879.
  9. Hwang, J.S., Huang, Y.N., Wang, S.J. and Hung, C.F. (2010), "Design force transmitted by isolation system composed of lead-rubber bearings and viscous dampers", Int. J. Struct. Stabil. Dyn., 10(2), 287-298. https://doi.org/10.1142/S0219455410003440.
  10. Hwang, J.S., Sheng, L.H. and Gates, J.H. (1994), "Practical analysis of bridges on isolation bearings with bi-linear hysteresis characteristics", Earthq. Spectra, 10(4), 705-727. https://doi.org/10.1193/1.1585794.
  11. Jangid, R.S. (2007), "Optimum lead-rubber isolation bearings for near-fault motions", Eng. Struct., 29(10), 2503-2513. https://doi.org/10.1016/j.engstruct.2006.12.010.
  12. Jara, M. and Casas, J.R. (2006), "A direct displacement-based method for the seismic design of bridges on bi-linear isolation devices", Eng. Struct., 28(6), 869-879. https://doi.org/10.1016/j.engstruct. 2005.10.016.
  13. Kalpakidis, I.V. and Constantinou, M.C. (2008), "Effects of heating and load history on the behavior of lead-rubber bearings", Report No. MCEER-08-0027, Multidisciplinary Center for Earthquake Engineering Research, State University of New York, Buffalo, U.S.A.
  14. Kelly, J.M. (1990), "Base isolation: linear theory and design", Earthq. Spectra, 6(2), 223-244. https://doi.org/10.1193/1.1585566.
  15. Kelly, J.M. (1996), Earthquake-resistant design with rubber, Springer Verlag, London, U.K.
  16. Kowalsky, M.J. (2002), "A displacement-based approach for the seismic design of continuous concrete bridges", Earthq. Eng. Struct. Dyn., 31(3), 719-747. https://doi.org/10.1002/eqe. 150.
  17. Lu, L.Y., Wang, L.W., Chen, C.H., Lee, K.F., Lee, T.Y. and Tsai, C.C. (2016), "Performance-oriented two-stage design method for base-isolated structures", Struct. Eng., 31(3), 33-61. https://doi.org/ 10.6849/SE.201609_31(3).0002.
  18. Seismic design code for buildings (2011), Ministry of Interior, Taipei, Taiwan.
  19. Zhao, Y.G., Zhang, H., and Saito, T. (2017), "A simple approach for the fundamental period of MDOF structures", Earthq. Struct., 13(3), 231-239. http://dx.doi.org/10.12989/eas.2017.13.3.231.