An experimental study of fault slips under unloading condition in coal mines

Abstract To investigate the mechanism of fault slips in coal mines, a biaxial shear experiment was carried out under unloading condition based on F16 Yima city, China. Two rock samples were used and each sample composed two triangular sandstone blocks which put together to simulate fault. One do slip tests it called slip-test sample. The other for comparison with one untested, named non-slip-test During sample, normal strains near fault, acoustic emission (AE) signals, sliding displacement measured. After experiment, microscopic profiles surfaces both examined by scanning electron microscope (SEM). In addition, numerical simulation conducted model F16. results indicate that: (1) three occurred during stress, first showed maximum variation among slips; (2) Shear ends had more significate than that middle part, typical trend dropping, then increasing rapidly, falling slowly specific value slip; (3) largest 29.89 $$\mu m$$ μ m , phases including slow slip, main shock aftershock AE monitoring results. (4) On surface microstructures such as bulges, voids veins ubiquitous notable, making much rough, while similar few flattened after (5) slipping direction shallow part deep opposite mining.