Failure Mechanism and Control of Lower Retracement Channel in Close-Distance Double-Thick Coal Seams

Table 4

Comparison between theoretical prediction and simulation results.

Coal pillar aspect ratio	Safety factor (FOS) calculation value	Theoretical prediction results	Simulation results
1	0.38	Unstable	Unstable
2	0.83	Critical stable	Critical stable
3	1.32	Stable	Stable
4	1.82	Stable	Stable
5	2.34	Absolute stable	Stable