Study on seepage characteristics and visualization of coal and rock under coupled stress-strain-seepage conditions

The permeability of coal and rock determines the difficulty of gas flow, and the mechanical properties of coal and rock also affect the permeability of coal and rock to some extent. In order to investigate the changes of permeability characteristics of coal and rock under different stress-strain conditions, the permeability test of coal and rock was carried out and combined with computed tomography(CT) scanning to reconstruct the pore-fissure structure of coal samples in three dimensions. The evolution law of permeability characteristics of coal and rock was analyzed from the perspective of the change of pore-fissure of coal and rock coal pore under the influence of stress-strain. At the same time, Avizo software was used to simulate the visual gas flow and permeability value of the crushed coal samples. The results show that the permeability of coal and rock shows a V-shaped change with the increase of axial stress-strain; and the change of permeability is significantly correlated with the change of pore space inside the coal and rock; the permeability value of coal sample obtained by CT scanning is basically consistent with the permeability value obtained by test. The results can provide reference for the study of permeability and visualization of coal and rock under similar conditions.