Study on Water Seepage Law of Raw Coal During Loading Process

In order to reveal the water seepage law of raw coal during different loading process, the gravity constant load seepage experimental system is developed and used in this paper. The water seepage law of raw coal during different loading process was tested. The mathematical model of axial strain-damage-permeability coefficient during the loading process is proposed based on the Wei-bull distribution of coal damage. According to the water seepage experiments and results analysis, the following conclusions are gotten. Under the same experimental conditions, with the increasing of axial pressure, the permeability coefficient of coal sample has a distinct decrease trend, and then an increase trend when reached the extreme point. The same trend of permeability coefficient-strain curves and stress-strain curve of the raw coal samples under different axial pressure are got-ten, that mean the permeability coefficient is closely related to the damage evolution process. The water seepage law of raw coal during different loading process can be described by the mathematical model of axial strain-damage-permeability coefficient, and its parameters can be obtained easily. This research is important for revealing the mechanism of coal seam water seepage, guiding field coal seam water infusion, controlling mine water hazard, preventing coal mine disasters.