Research on Seepage Properties and Pore Structure of the Roof and Floor Strata in Confined Water-Rich Coal Seams: Taking the Xiaojihan Coal Mine as an Example

Table 4

Porosity of the roof and floor rock strata.

Sampling position	Distance from the coal seam (m)	Porosity (%)
Roof rock	70.9	8.7194
	64.8	1.889
	52.1	10.4468
	49.1	0.3389
	37.1	1.7468
	26.9	0.3562
	12.9	0.2146
	2.5	0.3588
Floor rock	−1.6	0.1985
	−9.3	0.2589
	−19.5	0.3033
	−27.6	1.8036
	−35.8	0.9951