Mechanical Characteristics of Coal and Rock in Mining under Thermal-Hydraulic-Mechanical Coupling and Dynamic Disaster Control

Table 2

Triaxial loading and unloading test results of the raw coal specimen.

Number	Temperature (°C)	Gas pressure (MPa)	σ1 (MPa)	σ3 (MPa)	At peak stress
					ε1 (10^−2)	ε3 (10^−2)	(10^−2)	μ
11-30-A1	30	1.0	31.08	2.95	1.75	−0.41	0.93	0.234
11-30-A2			32.16	3.01	1.88	−0.48	0.92	0.255
11-30-A3			33.27	3.15	1.94	−0.39	1.16	0.201
Mean			32.17	3.04	1.86	−0.43	1.00	0.230
Standard deviation			0.894	0.084	0.079	0.039	0.111	0.022
Coefficient of variation			0.028	0.028	0.043	0.090	0.110	0.097
11-40-B1	40	1.0	30.02	3.26	1.71	−0.41	0.89	0.240
11-40-B2			29.85	3.21	1.64	−0.39	0.86	0.238
11-40-B3			28.96	3.18	1.62	−0.37	0.88	0.228
Mean			29.61	3.22	1.66	−0.39	0.88	0.235
Standard deviation			0.465	0.033	0.039	0.016	0.012	0.005
Coefficient of variation			0.016	0.010	0.023	0.042	0.014	0.021
11-50-C1	50	1.0	26.85	3.37	1.49	−0.35	0.79	0.235
11-50-C2			27.63	3.34	1.53	−0.37	0.79	0.242
11-50-C3			28.57	3.29	1.60	−0.38	0.84	0.238
Mean			27.68	3.33	1.54	−0.37	0.81	0.238
Standard deviation			0.703	0.033	0.045	0.012	0.024	0.003
Coefficient of variation			0.025	0.010	0.030	0.034	0.029	0.012
11-60-D1	60	1.0	26.56	3.42	1.42	−0.35	0.72	0.246
11-60-D2			25.89	3.38	1.35	−0.33	0.69	0.244
11-60-D3			25.75	3.34	1.32	−0.31	0.70	0.235
Mean			26.07	3.38	1.36	−0.33	0.70	0.242
Standard deviation			0.353	0.033	0.042	0.016	0.012	0.005
Coefficient of variation			0.014	0.010	0.031	0.049	0.018	0.021
11-70-E1	70	1.0	25.01	3.48	1.14	−0.30	0.54	0.263
11-70-E2			24.78	3.45	1.11	−0.27	0.57	0.243
11-70-E3			23.95	3.41	1.06	−0.25	0.56	0.236
Mean			24.58	3.45	1.10	−0.27	0.56	0.247
Standard deviation			0.455	0.029	0.033	0.021	0.012	0.012
Coefficient of variation			0.019	0.008	0.030	0.075	0.022	0.047