Modifications for the smooth joint contact model in the particle flow code

M. H. Mehranpour, Pinnaduwa Kulatilake

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


This paper deals with the following two shortcomings of the smooth joint contact model (SJCM) used in the particle flow code (PFC): (a) Use of a constant value for joint normal stiffness instead of allowing actual non-linear behavior between the joint normal deformation and joint normal stress; (b) The so called "interlocking problem". The first one is solved by imposing a linear relation between the joint normal stiffness and the normal contact stress in a new modified smooth-joint contact model (MSJCM). A good agreement obtained between the results from the experimental tests and the numerical modeling of the compression joint normal test, shows the accuracy of this new model. The second shortcoming occurs due to a lack of an updating procedure in the PFC software related to the contact conditions of the particles that lie around the intended joint plane during high shear displacements. This problem increases the shear strength of the joint when the shear displacement of the joint exceeds a specific value and creates unwanted fractures around the intended joint plane. To solve this problem a new approach termed joint side checking (JSC) is proposed. Numerical modeling of the direct shear test shows JSC can solve the interlocking problem and proves to be more consistent with the theory compared to the regular approach.

Original languageEnglish (US)
Title of host publication51st US Rock Mechanics / Geomechanics Symposium 2017
PublisherAmerican Rock Mechanics Association (ARMA)
Number of pages7
ISBN (Electronic)9781510857582
StatePublished - Jan 1 2017
Event51st US Rock Mechanics / Geomechanics Symposium 2017 - San Francisco, United States
Duration: Jun 25 2017Jun 28 2017


Other51st US Rock Mechanics / Geomechanics Symposium 2017
CountryUnited States
CitySan Francisco

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

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