The Porosity Dynamic Model of the Compacted Broken Coal

Table 5

The results of the fractal porosity of the compacted broken coal.

Coal sample	Axial stress (MPa)	Fractal dimension	Axial strain	Experimental result	Theoretical model: formula (15)	Relative error (%)
1#	9	2.5064	0.1755	0.0545	0.0526	3.5
2#	12	2.5054	0.1864	0.0425	0.0437	2.8
3#	15	2.5531	0.2159	0.0243	0.0228	6.2