Variation in the Permeability of Intact and Fractured Rocks due to Transient Disturbances in Axial Stress or Pore Pressure

Table 5

Experimental condition for the Shikotsu welded tuff.

Axial stress disturbance							Pore pressure disturbances
Samples	Constant hydrostatic stress			Transient axial stress			Constant hydrostatic stress			Transient pore pressure
	PC	PP	σA	ΔσA	σA-min	σA-max	Samples	PC	PP	ΔPP	PP-min	PP-max
AS-T1	5	0.5	5	0	5	5	Pp-T1	5	0.5	0	0.5	0.5
AS-T2							Pp-T2
AS-T3							Pp-T3
AS-T4				8	1	9	Pp-T4			0.1	0.45	0.55
AS-T5							Pp-T5
AS-T6							Pp-T6
AS-T7		0.1		0	5	5	Pp-T7			0.8	0.1	0.9
AS-T8							Pp-T8
AS-T9							Pp-T9
AS-T10				8	1	9	Pp-T10		0.1	0	0.1	0.1
AS-T11							Pp-T11
							Pp-T12
							Pp-T13			0.06	0.07	0.13
							Pp-T14
							Pp-T15

P_C: confining pressure; P_P: pore pressure; Δσ_A: axial stress disturbance amplitude; ΔP_P: pore pressure disturbance amplitude; P_P-min: minimum pore pressure; P_P-max: maximum pore pressure. Unit of stresses is mega Pascal (MPa).