Gob-Side Entry Retaining Technology with Advanced Empty Hole Butterfly-Shaped Weakening in Three-Soft Coal Seam in China

Table 2

Extreme values of stresses at different hole spacings.

Hole spacing (L/cm)	Single hole	L = 0.5D	L = 1.0D	L = 2.0D	L = 3.0D	L = 4.0D	L = 5.0D
Maximum stress (MPa)	4.40	5.43	4.76	4.53	4.48	4.40	4.40
Minimum stress (MPa)	0.51	0.49	0.51	0.51	0.51	0.51	0.51