Comparative Analyses Concerning Triaxial Compressive Yield Criteria of Coal with the Presence of Pore Water

Table 2

Test results concerning ultimate strength of coal samples.

Category	(MPa)	Coulomb criterion			Parabolic Mohr criterion			Hoek-Brown criterion			Quadratic polynomial criterion
		(MPa)	(°)	(MPa)	(MPa)	(MPa)	(MPa)		(MPa)	(MPa)		(MPa)	(MPa)	(MPa)
DT natural	15.879	10.05	29.13	6.35	26.7	0.0001688	4.53	17.44	16.08	2.42	10.29	16.39		0.88
BD natural	30.16	12.71	32.55	5.56	37.87		4.47	14.93	30.16	2.55	8.338	30.16	8.61	1.66
XH natural	21.07	7.454	38.15	2.98	29.75	0.006519	6.22	19.61	21.07	1.86	17.51	21.07	14.95	1.80
YC natural	17.68	5.096	31.31	3.74	20.32		3.00	10.79	18.13	2.30	5.484	18.01	0.0002742	1.90
DT water-saturated	11.638	3.382	34.02	5.25	20.37		5.31	15.91	12.18	3.27	10.89	12.45		2.64
DT seepage		10.17	29.36	2.27	23.23		2.72	9.546	24.44	2.16	35.34	6.406	0.05028	2.16
BD seepage		3.348	40.08	1.24	15.15	0.00016	2.67	1859	0.1197	1.48	1608	26.19		3.27
XH seepage		4.84	24.23	0.29	8.959		0.25	5.197	12.56	0.22	6.578	6.873		0.14