A Dynamic Numerical Simulation on the Grouting Timing in Retained Rib of Pillarless Mining

A dynamic numerical method is established to simulate the stability of surrounding rocks retained roadway in FLAC3D, along with a double-yield constitutive model re-compaction process gangue and strain-softening characteristic coal grouted fragmented after yielding. The simulation reveals that grouting slurry diffusion range, mining affecting stage behind working face rib deformation are closely interrelated. Under severe mining-induced stress, integrity rock more likely be destroyed, accompanied by large number cracks developing gradually expanding rocks. increases rapid manner. Meanwhile, diffusing range gradually. conducted this study indicates optimum support effect can achieved section before affected high stress. timely used construct an enhanced rock-bolting-grouting system maintain roadway.