Fig. 7

Amplitude, Cumulative ring-down counts versus time during the process of unloading confining pressure: (a) 1 MPa; (b) 5 MPa; (c) 10 MPa; (d) 20 MPa; (e) 40 MPa; (f) 50 MPa.

Amplitude, Cumulative ring-down counts versus time during the process of unloading confining pressure: (a) 1 MPa; (b) 5 MPa; (c) 10 MPa; (d) 20 MPa; (e) 40 MPa; (f) 50 MPa.