Study on the Porosity of Saturated Fragmentized Coals during Creep Process and Constitutive Relation

Table 2

Fitted equation coefficients of fragmentized coals under different axial stresses.

Grain size (in mm)	Regression coefficient	Axial stress: 8 MPa	Axial stress: 12 MPa
m1 (20–25)	A	0.1548	0.1120
	B	0.2839	0.0233
	C	0.0676	0.1800
m2 (15–20)	A	0.1860	0.1738
	B	0.0538	0.0483
	C	0.1118	0.1375
m3 (10–15)	A	0.1623	0.1225
	B	0.0231	0.0365
	C	0.0815	0.1430
m4 (5–10)	A	0.1708	0.1403
	B	0.0250	0.0071
	C	0.0845	0.1075
m5 (2.5–5)	A	0.2121	0.1723
	B	0.0141	0.0150
	C	0.1187	0.0865