Fracture and seepage characteristics in the floor strata when mining above a confined aquifer
Abstract：A quantitative relationship for the fractured rock permeability coefficient was obtained by conducting stress-strain permeability tests on intact and fractured rock samples. The stress seepage coupling mechanism is elucidated from these results. Mining a lower coal seam located above a confined aquifer in Shanxi province motivated this research. A discrete element numerical model was used to simulate fluid-solid coupling and determine stress and seepage in the floor strata. Four typical zones appear in the floor strata that are closely related to the hori- zontal stress. The damage state and the permeability are used to define these zones. If the di- rect floor stratum is seriously affected by mining induced pressure the horizontal stress is disor- dered and the damaged zone is about 13 m thick. The confining pressure in the strata above the Ordovician aquifer is low and hydraulic splitting fractures it easily. The thickness of the zone where water rises is about 17 m. The middle of the floor strata are less affected by mining and the confined aquifer. The horizontal stresses increase with increasing depth the water resisting layer is about 38m. This is the zone that provides the layer in the floor. and the thickness of key water resistant layer in the floor.
Keywords：confined aquiferseepage in fracturediscrete elementfluid-solid couplingkey water-resisting layer
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 536-542 )