Mechanical Characteristics of Coal Samples under Triaxial Unloading Pressure with Different Test Paths

Table 1

Triaxial compression test results.

Lithology	Confining pressure (MPa)	Axial stress difference (MPa)	Damage stress (MPa)	Inflection point ratio	Peak circumferential strain (mm/mm)	Peak axial strain (mm/mm)	Elastic modulus (MPa)	Poisson ratio
Coal	4	32. 22	30.12	82.81%	−0.00202	0.00588	5522	0.23
	7	38.07	33.21	73.22%	−0.00250	0.00689	6674	0.23
	10	48.87	—	—	−0.00263	0.00781	6680	0.31