Stability Influencing Factors and Control Methods of Residual Coal Pillars with Solid Waste Materials Backfilling Method

Affected by coal mining activities, the remaining pillars are very likely to be destabilized and cause safety accidents. The backfilling of goaf can maintain stability pillar well, but in unfilled zone may still unstable. In this paper, effect materials on reinforcement method discussed using numerical simulation, statistical mathematics, elastic mechanics, mechanical test methods. results show that: with solid waste reinforcing could bottom goaf, where backfill body height is main factor strength pillar. propagation confining stress primary way influence strength. Changing filling affect By analyzing law pillar, minimum determined 7 m. Combined tests Mohr–Coulomb criterion, pressure required under peak ground analyzed. ratio based this. Field have proved that remains stable when not filled, cement/fly ash 1:4, which ensure product safety. research has significant value significance for governance production