Cracking Mode Analysis of Crack Initiation in Rocks under Uniaxial Compression

Table 2

Comparisons of the results used for determining the crack initiation stress.

No.	Rock type	E (GPa)	μ	Strength (MPa)	CMA		CVS		LSR
					Stress (MPa)	Stress ratio	Stress (MPa)	Stress ratio	Stress (MPa)	Stress ratio
A	Tight sandstone	18.3	0.17	80.6	43.3	0.54	30.8	0.38	31.1	0.39
B		23.4	0.16	103.8	32.6	0.31	37.7	0.36	37.1	0.36
C		14.3	0.13	72.2	36.2	0.50	29.8	0.41	33.2	0.46
Mean		18.7	0.16	85.6	37.4	0.45	32.8	0.39	33.8	0.40
D	Loose sandstone	5.2	0.40	27.3	9.3	0.34	10.9	0.40	9.2	0.34
E		4.9	0.28	29.5	6.4	0.22	10.5	0.35	9.9	0.34
F		5.5	0.35	36.8	15.2	0.41	14.0	0.38	8.6	0.23
G		5.9	0.42	36.4	14.0	0.39	13.6	0.37	12.3	0.34
Mean		5.4	0.36	32.5	11.3	0.34	13.1	0.40	10.0	0.31
H	Granite	41.9	0.21	123.0	40.13	0.33	49.4	0.40	58.5	0.48
I		41.4	0.19	124.1	31.21	0.32	40.3	0.32	62.9	0.51
J	Granite	38.0	0.17	102.0	40.52	0.40	41.1	0.40	66.4	0.65
Mean		40.4	0.19	116.4	37.29	0.35	43.6	0.38	62.6	0.54