Issue 44

X.-P. Zhou et alii, Frattura ed Integrità Strutturale, 44 (2018) 64-81; DOI: 10.3221/IGF-ESIS.44.06

Figure 6 : Comparison of predicted strength and the experimental data of Barre granite.

Figure 7 : Comparison of predicted strength and the experimental data of Jinping marble

D ISCUSSIONS AND C ONCLUSIONS

n this paper, Burgers model with the characteristics of instantaneous elastic deformation, primary creep and steady rate creep is applied to investigate creep fracture behaviors of penny-shaped microcracks. Mode II stress intensity factor at tips of three-dimensional penny-shaped microcracks embedded in Burgers viscoelastic rock matrix is derived. The orientation angle of micro-failure in Burgers viscoelastic rocks is defined . A novel micromechanics-based three dimensional long-term strength criterion is proposed to investigate effects of time and the intermediate principal stress on I

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