Analysis of Failure Characteristics and Strength Criterion of Coal-Rock Combined Body with Different Height Ratios

Table 3

M-C criterion fitting parameters and R².

	Fitting curve	R^2	Cohesion	The angle of internal friction (MPa)	Theoretical value	Actual value
0	σ1 = 51.345 + 3.761σ3	0.968	13.24	35.4	27.3	22.9
0.75	σ1 = 5.37 + 1.277σ3	0.973	2.37	6.98	41.5	38.3
0.67	σ1 = 5.29 + 1.848σ3	0.922	1.94	17.32	36.33	40.9
0.5	σ1 = 6.38 + 2.158σ3	0.915	2.17	21.5	34.24	35.2
0.33	σ1 = 8.27 + 2.418σ3	0.917	2.65	24.5	32.74	29.4
1	σ1 = 5.81 + 1.32σ3	0.967	2.52	7.93	41.03	42.5