Study on the water-conducting evolution laws of faults based on the dynamic evolution of permeability coefficient

To examine how the permeability of surrounding rock and fault-related water conduction evolve during mining-induced disturbances, this study adopts theoretical analysis methods.The Mohr-Coulomb and maximum tensile criteria were used to develop a mathematical model that describes sudden changes in permeability caused by stress and water pressure.This model was integrated into FLAC^3D simulation software to create a dynamic characterization of permeability mutations.A case study in a Shandong mining area employed this numerical simulation approach to simulate the activation of floor faults and the subsequent formation of water inrush events.The simulations revealed the staged evolution of fault permeability and the elevation of pressure-driven water conduction during mining.Key findings include: the elevation of pressure-driven water conduction lags significantly behind fault activation, with hydraulic fracturing effects persisting even after mining stops.Conduction velocity increases with burial depth and initial fault permeability.Shallower faults exhibit smaller permeability changes and slower water conduction, while higher initial permeability reduces energy loss and accelerates water movement.These results offer valuable insights for preventing water hazards in mining operations, particularly in areas prone to fault activation and delayed water inrush.