Research on Coal Mechanical Properties Based on True Triaxial Loading and Unloading Experiment

Table 1

True triaxial loading and unloading test data.

	True triaxial loading test				True triaxial unloading test
Specimen number	1-L	2-L	3-L	4-L	1-U	2-U	3-U	4-U
σ1 (MPa)	44.2	59.5	50.9	60.1	39.8	53.5	45.8	54.1
σ2 (MPa)	3	6	9	12	3	6	9	12
σ3 (MPa)	2				2
Loading rate (MPa·s^−1)	0.2				0.2
Unloading rate (MPa·s^−1)	0.5				0.5