Structural Engineering and Mechanics

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Evaluating the effective spectral seismic amplification factor on a probabilistic basis

  • Makarios, Triantafyllos K. (Institute of Engineering Seismology and Earthquake Engineering)
  • Received : 2011.05.16
  • Accepted : 2012.02.29
  • Published : 2012.04.10
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Abstract

All contemporary seismic Codes have adopted smooth design acceleration response spectra, which have derived by statistical analysis of many elastic response spectra of natural accelerograms. The above smooth design spectra are characterized by two main branches, an horizontal branch that is 2.5 times higher than the peak ground acceleration, and a declining parabolic branch. According to Eurocode EN/1998, the period range of the horizontal, flat branch is extended from 0.1 s, for rock soils, up to 0.8 s for softer ones. However, from many natural recorded accelerograms of important earthquakes, the real spectral amplification factor appears to be much higher than 2.5 and this means that the spectrum leads to an unsafe seismic design of the structures. This point is an issue open to question and it is the object of the present study. In the present paper, the spectral amplification factor of the smooth design acceleration spectra is re-calculated on the grounds of a known "reliability index" for a desired probability of exceedance. As a pilot scheme, the seismic area of Greece is chosen, as it is the most seismically hazardous area in Europe. The accelerograms of the 82 most important earthquakes, which have occurred in Greece during the last 38 years, are used. The soil categories are taken into account according to EN/1998. The results that have been concluded from these data are compared with the results obtained from other strong earthquakes reported in the World literature.

Keywords

References

  1. Bendat, J. and Piersol, A. (2000), Random Data. Analysis and Measurement Procedures, Third Edition, John Wiley & Sons, Inc Publication, USA.
  2. Beyer, K. and Bommer, J.J. (2007), "Selection and scaling of real accelerograms for bi-directional loading: A review of current practice and Code provisions", J. Earthq. Eng., 11, 13-45.
  3. Bradley, A.B., Dhakal, P.R., MacRae, A.G. and Cubrinovski, M. (2010), "Prediction of spatially distributed seismic demands in specific structures: Ground motion and structural response", Earthq. Eng. Struct. D., 39, 501-520.
  4. EN/1998: Eurocode No8 (2004), "Design of structures for earthquake resistance - Part 1: General rules, seismic actions and rules for buildings", European Committee for Standardization, Brussels.
  5. EN/1990: Eurocode No0 (2002), "Basis of structural design", European Committee for Standardization, Brussels.
  6. Gazetas, G. (2006), "Seismic design of foundations and soil-structure interaction", Proceedings of the 1st European Conference on Earthquake Engineering and Seismology, Geneva, Switzerland, September.
  7. Jun, D. (2010), "Seismic response of r/c structures subjected to simulated ground motions compatible with design spectrum", Struct. Design Tall Spec. Build., DOI:10.1002/tal.658.
  8. Mylonakis, G. and Gazetas, G. (2000), "Seismic soil-structure interaction: beneficial or detrimental?", J. Earthq. Eng., 4(3), 277-301.
  9. Theodoulidis, N., Kalogeras, I., Papazachos, C., Karastathis, V., Margaris, B., Papaioannou, Ch., Skarlatoudis. (2004), "A. HEAD 1.0: A unified hellenic accelerogram database", Seismol. Res. Lett., 7(1), 36-45.
  10. Tothong, P. and Luco, N. (2007), "Probabilistic seismic demand analysis using advanced ground motion intensity measures", Earthq. Eng. Struct. D., 36, 1837-1860. https://doi.org/10.1002/eqe.696
  11. Xu, L. and Xie, L. (2004), "Bi-Normalized response spectral characteristics of the 1999 Chi-ChiEarthquake", Earthq. Eng. Eng. Vib., 3(2), December.
  12. Ziotopoulou, A. and Gazetas, G. (2010), "Are current design spectra sufficient for soil-structure systems on soft soils?", Advances in Performance-Based Earthquake Engineering, Chapter 8, Ed. M.N. Fardis, Springer Verlag, Berlin.

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