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Experimental Investigation on the Crack Propagation and Coalescence in Rock-Like Specimens with Pre-existing Cracks Under Compressive Loading

  • Seyed Alireza Fatemi
  • Ahmad FahimifarEmail author
Conference paper
Part of the Sustainable Civil Infrastructures book series (SUCI)

Abstract

The mechanical behavior of a rock mass is ruled by its embedded discontinuities such as cracks and joints. Uniaxial compression experiments were carried out on rock-like materials with man-made flaws to study the effects of flaw parameters on the mechanical behavior of rock samples under uniaxial compression. Crack initiation, propagation and coalescence near the pre-existing cracks were investigated by rock-like cylinder shaped specimens with different geometries. The samples were prepared by increasing the angle of the flaws by 15°, and the number of pre-existing flaws. The flaws were made by pulling out a metal shim located in the sample before a curing process. Based on complete axial stress–strain curves of the loading process using a servo-controlled testing system, the effect of flaw geometry and number of flaws on the strength and deformation behavior of specimens were fully analyzed. Also, crack propagation and coalescence mechanisms, leading to progressive failure processes in rock masses under compressive loading were carefully observed with a high speed recording digital camera. In all samples, it was observed that wing cracks produced at the first stage of loading and propagate in the direction of uniaxial compressive loading. Moreover, it is shown that the uniaxial compressive strength, elastic modulus and peak axial strain of specimens with pre-existing flaws are lower than those of the specimens without pre-existing flaws. The mechanism of crack initiation, propagation and coalescence is described in the present study and the outcomes are summarized according to various parameters.

References

  1. 1.
    Bobet, A.: The initiation of secondary cracks in compression. Eng. Fract. Mech. 66(2), 187–219 (2000)CrossRefGoogle Scholar
  2. 2.
    Cao, P., Liu, T., Pu, C., Lin, H.: Crack propagation and coalescence of brittle rock-like specimens with pre-existing cracks in compression. Eng. Geol. 187, 113–121 (2015)CrossRefGoogle Scholar
  3. 3.
    Chen, X., Liao, Z.H., Peng, X.: Cracking process of rock mass models under uniaxial compression. J. Cent. South Univ. Technol. 20, 1661–1678 (2013)CrossRefGoogle Scholar
  4. 4.
    Diederichs, M.S., Kaise, P.K., Eberhardt, E.: Damage initiation and propagation in hard rock during tunneling and the influence of near-face stress rotation. Int. J. Rock Mech. Min. Sci. 41(5), 785–812 (2004)CrossRefGoogle Scholar
  5. 5.
    Lee, H., Jeon, S.: An experimental and numerical study of fracture coalescence in precracked specimens under uniaxial compression. Int. J. Solids Struct. 48(6), 979–999 (2011)CrossRefGoogle Scholar
  6. 6.
    Li, H.Q., Li, H.Q.: Numerical study on coalescence of two pre-existing coplanar flaws in Rock. Int. J. Solids Struct. 50(22), 3685–3706 (2013)Google Scholar
  7. 7.
    Liu, T., Lin, B., Zheng, C., Zou, Q., Zhu, C., Yan, F.: Influence of coupled effect among flaw parameters on strength characteristic of precracked specimen: application of response surface methodology and fractal method. J. Nat. Gas Sci. Eng. 26, 857–866 (2015)CrossRefGoogle Scholar
  8. 8.
    Manouchehrian, A., Sharifzadeh, M., Marji, M.F., Gholamnejad, J.: A bonded particle model for analysis of the flaw orientation effect on crack propagation mechanism in brittle materials under compression. Arch. Civil Mech. Eng. 14(1), 40–52 (2014)CrossRefGoogle Scholar
  9. 9.
    Sagong, M., Park, D., Yoo, J., Lee, J.S.: Experimental and numerical analyses of an opening in a jointed rock mass under biaxial compression. Int. J. Rock Mech. Min. Sci. 48(7), 1055–1067 (2011)CrossRefGoogle Scholar
  10. 10.
    Wang, Q.Z., Yang, J.R., Zhang, C.G., Zhou, Y., Li, L., Zhu, Z.M., Wu, L.Z.: Sequential determination of dynamic initiation and propagation toughness of rock using an experimental–numerical–analytical method. Eng. Fract. Mech. 141, 78–94 (2015)CrossRefGoogle Scholar
  11. 11.
    Zhang, X.P., Wong, L.N.Y.: Crack initiation, propagation and coalescence in rock-like material containing two flaws: a numerical study based on bonded-particle model approach. Rock Mech. Rock Eng. 46(5), 1001–1021 (2013)CrossRefGoogle Scholar
  12. 12.
    Bobet, A., Einstein, H.H.: Fracture coalescence in rock-type materials under uniaxial and biaxial compression. Int. J. Rock Mech. Min. Sci. 35, 863–889 (1998)CrossRefGoogle Scholar
  13. 13.
    Trivino, L.F., Mohanty, B.: Assessment of crack initiation and propagation in rock from explosion-induded stress waves and gas expansion by cross-hole seismometry and FEM-DEM method. Int. J. Rock Mech. Min. Sci. 77, 287–299 (2015)CrossRefGoogle Scholar
  14. 14.
    Jiang, M., Chen, H., Crosta, G.B.: Numerical modeling of rock mechanical behavior and fracture propagation by a new bond contact model. Int. J. Rock Mech. Min. Sci. 78, 170–180 (2015)Google Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Civil and Environmental EngineeringAmirkabir University of TechnologyTehranIran

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