Numerical modeling of in-situ rock mass testing using extra large flat jack test

Ali Mortazavi, Ferri P. Hassani, Vahid Saati

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Modelling of extra large flat jack (ELFJ) testing at the Bakhtiyari dam site, Iran is the subject of this study. A complete 3D model of dam abutment, exploration gallery, and test set up was constructed. The aim was to reproduce the in-situ test results and determine the extra large jack coefficients manufactured by INTERFELS Corporation. In typical practice the large flat jack (LFJ) coefficients proposed by LNEC is used to calculate the final modulus data. These coefficients are also used to calculate the modulus data from ELFJ, which leads to significant errors. In this study a precise 3D numerical model of typical flat jack test condition was constructed using the Flac-3D code. Accordingly, the flat jack tests conducted at Bakhtiyari dam site, Iran, was simulated numerically. A very good agreement was achieved between numerical and field test results. Moreover, the obtained numerical results provided the coefficients of extra large flat jack. These, coefficients were employed for calculating the in-situ deformation modulus of Bakhtiyari dam rock mass.

Original languageEnglish
Title of host publicationISRM Regional Symposium, EUROCK 2015
PublisherInternational Society for Rock Mechanics
Number of pages6
ISBN (Print)9783950389814
Publication statusPublished - Jan 1 2015
Externally publishedYes
EventISRM Regional Symposium, EUROCK 2015 - Salzburg, Austria
Duration: Oct 7 2015Oct 10 2015

Publication series

NameISRM Regional Symposium, EUROCK 2015


ConferenceISRM Regional Symposium, EUROCK 2015

ASJC Scopus subject areas

  • Geophysics
  • Geotechnical Engineering and Engineering Geology

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