Investigating Effects of Individual Fracture Length on Behaviour of Weak Rock Using Discrete Element Method

  • Xiangyu Zhang
  • Behzad Fatahi
  • Hadi Khabbaz
Conference paper
Part of the Sustainable Civil Infrastructures book series (SUCI)


In this paper weak rock specimens with different individual fracture lengths are numerically simulated using the discrete element method (DEM). Effects of micro or macro-mechanical responses of intact and fractured specimens subjected to triaxial test have been studied. Various individual fracture lengths with a given fracture density within the weak rock specimens were reproduced using the particle flow code in three-dimension software (PFC3D). Different lengths of fractures were simulated by altering the size of each fracture to give insight over the influence of continual fractures and non-persistent fractures within bonded assemblies. As expected, for a given fracture density the individual fracture length affected the strength and deformability of rock mass. For an individual fracture length to specimen width ratio (the normalized fracture length) less than a limiting value, the effects of the individual fracture length on the stress-strain behaviour of rock specimens were more evident. Indeed, the strength decreased with decreasing the normalized fracture length. However, with a ratio above the limiting value, the effects of the individual fracture length were minimal. It can be concluded that for a given fracture density, present of shorter mini-fractures could be potentially more detrimental to stiffness and strength of the rock mass in comparison to longer major fractures.


  1. Bahaaddini, M., Sharrock, G., Hebblewhite, B.: Numerical investigation of the effect of joint geometrical parameters on the mechanical properties of a non-persistent jointed rock mass under uniaxial compression. Comput. Geotech. 49, 206–225 (2013)CrossRefGoogle Scholar
  2. Bieniawski, Z.T.: Mechanism of brittle fracture of rock: part I—theory of the fracture process. Int. J. Rock Mech. Mining Sciences & Geomechanics Abstracts, vol. 4, Elsevier, pp. 395IN11405-11404IN12406 (1967)CrossRefGoogle Scholar
  3. Chiu, C.-C., Wang, T.-T., Weng, M.-C., Huang, T.-H.: Modeling the anisotropic behavior of jointed rock mass using a modified smooth-joint model. Int. J. Rock Mech. Min. Sci. 62, 14–22 (2013)Google Scholar
  4. Ding, X., Zhang, L., Zhu, H., Zhang, Q.: Effect of model scale and particle size distribution on PFC3D simulation results. Rock Mech. Rock Eng. 47(6), 2139–2156 (2014)CrossRefGoogle Scholar
  5. Goodman, R.E., Ahlgren, C.S.: Evaluating safety of concrete gravity dam on weak rock: Scott Dam. J. Geotechnical Geoenvironmental Eng. 126(5), 429–442 (2000)CrossRefGoogle Scholar
  6. Klein, S.: An approach to the classification of weak rock for tunnel projects. In: Proceedings of the Rapid Excavation and Tunneling Conference, pp. 793–806 (2001)Google Scholar
  7. Le, T.M., Fatahi, B.: Trust-region reflective optimisation to obtain soil visco-plastic properties. Eng. Comput. 33(2), 410–442 (2016)CrossRefGoogle Scholar
  8. Le, T.M., Fatahi, B., Khabbaz, H., Sun, W.: Numerical optimization applying trust-region reflective least squares algorithm with constraints to optimize the non-linear creep parameters of soft soil. Appl. Math. Model. 41, 236–256 (2017)CrossRefGoogle Scholar
  9. Nguyen, L., Fatahi, B.: Behaviour of clay treated with cement and fibre while capturing cementation degradation and fibre failure–C3F Model. Int. J. Plast 81, 168–195 (2016)CrossRefGoogle Scholar
  10. Nguyen, L., Fatahi, B., Khabbaz, H.: A novel model to simulate the behaviour of cement-treated clay under compression and shear. In Geo-China 2016, 152–158 (2016)CrossRefGoogle Scholar
  11. Nguyen, L., Fatahi, B., Khabbaz, H.: Development of a constitutive model to predict the behavior of cement-treated clay during cementation degradation: C3 model. Int. J. Geomech. 17(7), 04017010 (2017)CrossRefGoogle Scholar
  12. Nickmann, M., Spaun, G., Thuro, K.: Engineering geological classification of weak rocks. In: Proceedings of the 10th International IAEG Congress (2006)Google Scholar
  13. Pierce, M., Cundall, P., Potyondy, D., Mas Ivars, D.: A synthetic rock mass model for jointed rock rock mechanics: meeting Society’s challenges and demands. In: 1st Canada-US Rock Mechanics Symposium, Vancouver, vol. 1, pp. 341–349 (2007)CrossRefGoogle Scholar
  14. Potyondy, D., Cundall, P.: A bonded-particle model for rock. Int. J. Rock Mech. Min. Sci. 41(8), 1329–1364 (2004)CrossRefGoogle Scholar
  15. Prudencio, M., Jan, M.V.S.: Strength and failure modes of rock mass models with non-persistent joints. Int. J. Rock Mech. Mining Sci. 44(6), 890–902 (2007)CrossRefGoogle Scholar
  16. Santi, P.M.: Field methods for characterizing weak rock for engineering. Environ. Eng. Geosci. 12(1), 1–11 (2006)CrossRefGoogle Scholar
  17. Sun, D.A., Feng, T., Matsuoka, H.: Stress–strain behaviour of weathered weak rock in middle-sized triaxial tests. Can. Geotech. J. 43(10), 1096–1104 (2006)CrossRefGoogle Scholar
  18. Tsoutrelis, C., Exadaktylos, G.: Effect of rock discontinuities on certain rock strength and fracture energy parameters under uniaxial compression. Geotech. Geol. Eng. 11(2), 81–105 (1993)CrossRefGoogle Scholar
  19. Yang, S., Jiang, Y., Xu, W., Chen, X.: Experimental investigation on strength and failure behavior of pre-cracked marble under conventional triaxial compression. Int. J. Solids Struct. 45(17), 4796–4819 (2008)CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

Authors and Affiliations

  1. 1.School of Civil and Environmental EngineeringUniversity of TechnologySydneyAustralia

Personalised recommendations