Issue 30

L. Zhang et alii, Frattura ed Integrità Strutturale, 30 (2014) 515-525; DOI: 10.3221/IGF-ESIS.30.62

100 120 140

100 120 140 160

0 20 40 60 80

0 20 40 60 80

 1 [MPa]  1 [MPa]

 1 [MPa]

0.000 0.003 0.006 0.009 0.012

0.000 0.002 0.004 0.006 0.008 0.010





(a) (b)

120 150 180

120 160 200

0 30 60 90

0 40 80

 1 [MPa]

0.000

0.005

0.010

0.015

0.000 0.003 0.006 0.009 0.012





(c) (d) Figure 9 : Stress-strain curves of conventional triaxial tests: (a) Confining pressure 10 MPa; (b) Confining pressure 20 MPa; (c) Confining pressure 30 MPa; (d) Confining pressure 40 MPa.

 1 [MPa]

 1 [MPa]





(a) (b)

 1 [MPa]



(c) Figure 10 : Stress-strain curves of different unloading rates: (a) Unloading rate of confining pressure 0.2 MPa/s; (b) Unloading rate of confining pressure 0.4 MPa/s; (c) Unloading rate of confining pressure 0.8 MPa/s.

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