Research on Influencing Factors of Effective Gas Extraction Radius in Coal Mine Based on Multiple Linear Regression

Table 5

Analysis of orthogonal array test results.

	Hole diameter (mm)	Extraction negative pressure (MPa)	Initial permeability of coal seam (×10^−17m^2)	Extraction time (d)
Kj1	2.83	2.89	1.63	1.29
Kj2	2.19	2.57	2.22	2.09
Kj3	2.34	2.3	3	3.09
Kj4	3.43	3.03	3.94	4.32
k1	0.7075	0.9633	0.5433	0.43
k2	0.5475	0.8567	0.74	0.6967
k3	0.585	0.7667	1	1.03
k4	0.8575	1.01	1.3133	1.44
R	0.31	0.2433	0.77	1.01