Study on Macro-Meso Deformation Law and Acoustic Emission Characteristics of Granular Gangue under Different Loading Rates

Bulk gangue is a common backfill material in solid mining. After backfilling into the goaf, bulk serves as main body to bear load of overlying strata, and its deformation resistance key factor affecting quality. In this study, laterally confined compression test broken was designed, compaction characteristics specimens under different loading rates were studied, acoustic emission (AE) energy analyzed, relationship model between macroscopic AE established. The particle flow numerical software PFC2D used stimulate breakage process, coal established through cluster units. force chain distribution fracture evolution process mechanism revealed from mesoscopic perspective. results showed that: porosity variation specimen increases with increase rate; decrease strain, decreases stress, stress monotonously decreasing. With rate, signals produced by become stronger, while influence rate on maximum fragmentation signal gradually weakened. Under rates, “instability-optimization” skeleton structure crushing-recombination cracks are reasons for at early stage loading. research great significance reveal materials compression.