Variation Law of Infrared Radiation Temperature of Unloading Fracture of Composite Coal-Rock

Table 3

Comparison of and peak stress parameters of coal body under different pressure relief rates.

Confining pressure unloading rate (MPa/s)	Sample			Stress
		Peak time (s)	Peak size (°C)	Peak time (s)	Peak size (MPa)
0.003	1^#	179.3	20.69	210.7	55.92
	2^#	180.7	20.52	213.9	57.67
	3^#	182.5	20.45	212.5	56.81
	4^#	179.1	20.66	210.3	55.70
	5^#	180.3	20.71	213.4	57.49
0.03	6^#	169.8	20.79	200.9	50.91
	7^#	170.4	20.73	199.8	50.69
	8^#	169.7	20.76	198.5	49.83
	9^#	168.6	20.75	201.3	49.74
	10^#	168.4	20.73	201.1	49.69
0.05	11^#	156.9	20.81	180.7	45.46
	12^#	157.1	20.92	183.4	46.79
	13^#	156.3	20.87	181.9	45.51
	14^#	155.8	20.94	177.1	45.39
	15^#	156.8	20.73	180.2	45.37

The symbol “#” constitutes the label of the “coal-rock-coal” sample, which is explained in Section 3.1.4.