Evolution of Floor Water Inrush from a Structural Fractured Zone with Confined Water

Due to a gradual increase in mining depths in northern China, the water inrush problem there has become increasingly complex. In the present study, a physical model was developed of a syncline-axis structural fractured zone above confined water, using measured parameters from the Baizhuang coal mine. Using the similarity theory, water inrush from a fractured floor was simulated with different water heads and different structural zones. The mechanism of a delayed water inrush from the floor under the combined action of confined water and a fractured zone was also studied. The results demonstrated that: (1) Water inflow under different pressures; (2) Sand inrush discharges gradually increased under various pressurized water pressures and then decreased; and (3) Based on water and sand inrush discharges, the changes in the Reynolds number and porosity were analyzed, and a “void flow-fissured flow-pipeline flow” transition was proposed. This research provides a basis for developing methods to prevent floor water inrush during deep mining.