The exact and approximate conditional spectra in the multi-seismic-sources regions

Hossein Ebrahimian, Alireza Azarbakht, Armin Tabandeh, Ali Akbar Golafshani

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


The exact and two approximate conditional spectra are compared in this manuscript as a target spectrum for the purpose of ground motion selection. The considered site is a real offshore site located at South Pars Gas Field in the Persian Gulf region. This case study site is influenced by four major seismic area sources in which the deaggregation results confirm that many comparable seismic scenarios can be taken into account. Therefore, an alternative to the conventional approximate conditional spectrum is proposed that has a small deviation from the exact solution. In addition, the use of different conditioning status of the probabilistic seismic hazard deaggregation (i.e., occurrence versus exceedance of the target spectral acceleration) for calculating the exact distribution of conditional spectrum was investigated. The results show that one of the proposed approximate approaches leads to conditional distributions which provide acceptable agreement with those obtained from the exact solution.

Original languageEnglish
Pages (from-to)61-77
Number of pages17
JournalSoil Dynamics and Earthquake Engineering
Publication statusPublished - 1 Aug 2012


  • conditional spectrum
  • nonlinear dynamic analysis
  • Persian Gulf region
  • probabilistic seismic hazard deaggregation
  • selection of ground motion records
  • dynamics
  • seismology
  • probability distributions
  • ground motion
  • seismic hazard
  • gas industry


Dive into the research topics of 'The exact and approximate conditional spectra in the multi-seismic-sources regions'. Together they form a unique fingerprint.

Cite this