Numerical simulation of coal seam floor water inrush based on acoustic emission technology

To clarify the precursor characteristics of coal seam floor water inrush under complex hydrogeological conditions and to provide a scientific basis for hazard monitoring and early warning, the damage evolution of the coal seam floor and water inrush induced by mining and collapse column were studied. The spatial and temporal characteristics of stress, seepage, fracture development, and acoustic emission (AE) responses were examined to reveal their indicative roles in water inrush initiation. A seepage—stress—damage coupling model was established by employing AE monitoring technology and RFPA2D-Flow numerical simulation. Mining-induced variations in mechanical fields, seepage fields, and AE signals were simulated to identify early-warning indicators associated with different inrush mechanisms. The results indicate that the high confining pressure of the Ordovician limestone aquifer is posed as a major threat to the stability of the coal seam floor. Distinct displacement distributions, abrupt increases in seepage, and abnormal AE activities can be taken as precursor signals of water inrush. A strong correlation is found between fracture propagation and AE energy release under pressurized conditions, and concentrated stress zones together with AE anomalies are shown to function as key warning signs. Simulations involving collapse columns further reveal a spatial correlation between peak stress and AE energy as the mining face advances. It is concluded that the combined evolution of stress concentration, fracture expansion, seepage intensification, and AE anomalies can be effectively used as early-warning indicators of floor water inrush. The findings provide critical insights for early hazard detection.