Analysis of Safety Interlayer Thickness of Gob Under Different Pillar Overlapping Ratio

The safety interlayer thickness is one of the important parameters of the stope stability. In order to get the safety interlayer thickness of multilayer gob in different pillar overlapping ratio, we analyze the change of plastic zone, the third principal stress, roof subsidence and side wall displacement. The results show that the pillar overlapping ratio is higher, the safety interlayer thickness is thinner, and the upper load can effectively transfer to the bottom. The safety interlayer thickness is 14 m, 10 m, 8 m when pillar overlapping ratio is 0%, 50%, 100%.