Fig. 7

Model validation curve: (a) Confining pressure 5Â MPa; (b) Confining pressure 10Â MPa; (c) Confining pressure 15Â MPa; (d) Confining pressure 20Â MPa.

Model validation curve: (a) Confining pressure 5Â MPa; (b) Confining pressure 10Â MPa; (c) Confining pressure 15Â MPa; (d) Confining pressure 20Â MPa.