Relationship between Brittleness Index and Crack Initiation Stress Ratio for Different Rock Types

Table 1

Summary of mechanical parameters of granite samples.

No.	σci (MPa)	σc (MPa)	σt (MPa)	α	σci/σc	Brittleness index
						B1	B2	B3	B4
H01	54.390	118.220	6.873	7.913	0.460	17.200	0.890	406.273	20.156
H02	56.136	109.424	7.017	8.000	0.513	15.594	0.879	383.914	19.594
H03	63.265	116.501	7.775	8.137	0.543	14.983	0.875	452.921	21.282
H04	55.176	116.983	6.754	8.169	0.472	17.320	0.891	395.074	19.876
H05	64.065	108.120	7.876	8.134	0.593	13.727	0.864	425.787	20.635
H06	78.165	117.100	9.371	8.342	0.668	12.497	0.852	548.644	23.423
H07	41.718	118.041	5.306	7.862	0.353	22.245	0.914	313.191	17.697
H08	64.635	135.280	8.770	7.370	0.478	15.425	0.878	593.230	24.356
H09	59.355	104.510	7.653	7.756	0.568	13.656	0.864	399.906	19.998
H10	74.160	101.500	9.564	7.754	0.731	10.613	0.828	485.382	22.031
H11	44.580	108.470	5.899	7.557	0.411	18.389	0.897	319.921	17.886
H12	40.815	124.665	5.161	7.909	0.327	24.157	0.920	321.679	17.935
H13	42.195	111.960	5.420	7.786	0.377	20.658	0.908	303.389	17.418