Geomechanics and Engineering

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Optimization of ground response analysis using wavelet-based transfer function technique

  • Moghaddam, Amir Bazrafshan (Department of Civil Engineering, Shahrood University) ;
  • Bagheripour, Mohammad H. (Faculty of Engineering, Shahid Bahonar University of Kerman)
  • Received : 2013.08.08
  • Accepted : 2014.04.12
  • Published : 2014.08.25
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Abstract

One of the most advanced classes of techniques for ground response analysis is based on the use of Transfer Functions. They represent the ratio of Fourier spectrum of amplitude motion at the free surface to the corresponding spectrum of the bedrock motion and they are applied in frequency domain usually by FFT method. However, Fourier spectrum only shows the dominant frequency in each time step and is unable to represent all frequency contents in every time step and this drawback leads to inaccurate results. In this research, this process is optimized by decomposing the input motion into different frequency sub-bands using Wavelet Multi-level Decomposition. Each component is then processed with transfer Function relating to the corresponding component frequency. Taking inverse FFT from all components, the ground motion can be recovered by summing up the results. The nonlinear behavior is approximated using an iterative procedure with nonlinear soil properties. The results of this procedure show better accuracy with respect to field observations than does the Conventional method. The proposed method can also be applied to other engineering disciplines with similar procedure.

Keywords

References

  1. Assimaki, D. and Li, W. (2012), "Site- and ground motion-dependent nonlinear effects in seismological model predictions", Soil Dyn. Earthq. Eng., 32(1), 143-151. https://doi.org/10.1016/j.soildyn.2011.06.013
  2. Bagheripour, M.H., Rahgozar, R. and Malekinejad, M. (2010), "Efficient analysis of SSI problems using infinite elements and wavelet theory", Geomech. Eng., Int. J., 2(4), 229-252. https://doi.org/10.12989/gae.2010.2.4.229
  3. Basu, B. and Gupta, V.K. (1998), "Seismic response of SDOF systems by wavelet modeling of nonstationary processes", J. Eng. Mech. ASCE, 124(10), 1142-1150. https://doi.org/10.1061/(ASCE)0733-9399(1998)124:10(1142)
  4. Bazrafshan, A. and Bagheripour, M.H. (2011), "Ground response analysis using non-recursive matrix implementation of hybrid frequency-time domain (HFTD) approach", Scientia Iranica, 18(6), 1188-1197. https://doi.org/10.1016/j.scient.2011.11.019
  5. Bazrafshan, A. and Bagheripour, M.H. (2012), "Earthquake time-frequency analysis using a new compatible wavelet function family", Earthq. Struct., Int. J., 3(6), 839-852. https://doi.org/10.12989/eas.2012.3.6.839
  6. Chang, C. and Shi, Y. (2010), "Identification of time-varying hysteretic structures using wavelet multiresolution analysis", Int. J. Non-Linear Mech., 45(1), 21-34. https://doi.org/10.1016/j.ijnonlinmec.2009.08.009
  7. Das, S. and Gupta, V.K. (2010), "Scaling of response spectrum and duration for aftershocks", Soil Dyn. Earthq. Eng., 30(8), 724-735. https://doi.org/10.1016/j.soildyn.2010.03.003
  8. Das, S. and Gupta, V.K. (2011), "A wavelet-based parametric characterization of temporal features of earthquake accelerograms", Eng. Struct., 33(7), 2173-2185. https://doi.org/10.1016/j.engstruct.2011.03.008
  9. EPRI Report (1993), Guidelines for Determining Design Basis Ground Motions, Vol. 2: Appendices for ground motion estimation; Appendix 6.B: in EPRI Technical Report No. TR-102293, Electric Power Research Institute.
  10. Hassani, B., Zafarni, H., Farjoodi, J. and Ansari, A. (2011), "Estimation of site amplification, attenuation and source spectra of S-waves in the East-Central Iran", Soil Dyn. Earthq. Eng., 31(10), 1397-1413. https://doi.org/10.1016/j.soildyn.2011.05.017
  11. Kausel, E. and Assimaki, D. (2002), "Seismic simulation of inelastic soils via frequency-dependent moduli and damping", J. Eng. Mech. - ASCE, 128(1), 34-47. https://doi.org/10.1061/(ASCE)0733-9399(2002)128:1(34)
  12. Kramer, S.L. (1996), Geotechnical Earthquake Engineering, Prentice-Hall International Series in Civil Engineering and Engineering Mechanics, Prentice-Hall, USA.
  13. Lee, V.W. and Trifunac, M.D. (2010), "Should average shear-wave velocity in the top 30 m of soil be used to describe seismic amplification", Soil Dyn. Earthq. Eng., 30(11), 1250-1258. https://doi.org/10.1016/j.soildyn.2010.05.007
  14. Misiti, M., Misity, Y., Oppenheim, G. and Poggi, J.M. (2011), Matlab Wavelet Toolbox User's Guide, The MathWorks Inc., USA.
  15. Obando, E.A., Ryden, N. and Ulriksen, P. (2011), "A mobile multi-depth borehole sensor set-up to study the surface-to-base seismic transfer functions", Engineering Geology, 123(3), 246-258. https://doi.org/10.1016/j.enggeo.2011.09.001
  16. Walnut, D.F. (2001), An Introduction to Wavelet Analysis, Birkhauser, Boston, MA, USA.

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