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Simulation of earthquake records using time-varying ARMA (2,1) model

Mobarakeh, A. A ; Sharif University of Technology | 2001

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  1. Type of Document: Article
  2. DOI: 10.1016/S0266-8920(01)00008-X
  3. Publisher: 2001
  4. Abstract:
  5. In this paper, the time-varying auto regressive moving average (ARMA) process is used as a simple yet efficient method for simulating earthquake ground motions. This model is capable of reproducing the nonstationary amplitude as well as the frequency content of the earthquake ground accelerations. The moving time-window technique is used to estimate the time variation of the model parameters from the actual earthquake records. The method is applied to synthesize the near field earthquakes, Naghan 1977, Tabas 1978, and Manjil 1990 recorded on dense soils in Iran, as well as the Mexico City 1985 earthquake recorded on a site with soft soil. It is shown that the selected ARMA (2,1) model and the algorithm used for generating the accelerograms are able to preserve the features of the real earthquake records with different frequency content. The moving time-window technique is used to estimate the time-varying ARMA parameters. Using a general guideline, it is found that a reasonable estimate of the moving window and overlapping sizes can be obtained with a few trials. The required window and overlapping sizes generally reduce, as the local soil of the site becomes stiffer. The statistical response and Fourier spectra of the simulated accelerograms are compared with those of the actual records and reasonable agreement was found. The relationship between the ARMA (2,1) model and the continuous Kanai-Tajimi model is also studied. It is shown that the parameters of the nonstationary Kanai-Tajimi model for simulation of artificial earthquakes can be evaluated using the present modeling procedure. © 2001 Published by Elsevier Science Ltd
  6. Keywords:
  7. ARMA ; Artificial earthquakes ; Synthetic earthquakes
  8. Source: Probabilistic Engineering Mechanics ; Volume 17, Issue 1 , 2001 , Pages 15-34 ; 02668920 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S026689200100008X