Citation

Ren C, Li B, Yang K, Li J, Zhang Y, Chen S. China Saf. Sci. J. 2019; 29(2): 63-68.

Copyright

(Copyright © 2019, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2019.02.011

PMID

unavailable

Abstract

In order to investigate the law of damage evolution and permeability evolution of coal during unstable failure process, relationships between volume fractal dimension of pore-fracture networks and stress and strain were introduced respectively. According to the relationship between volume fractal dimension of pore-fracture and stress, Weibull distribution parameters characterized by fractal dimension characteristics were derived. According to the relationship between the fractal dimension and porosity of pore-fracture of coal, variation (γ) of coal fractures with effective stress was solved. Based on Mohr-Coulomb criterion and Poiseuille law, a coal damage constitutive model and a permeability model considering the fractal effect were built. Then the relationship between damage and permeability was analyzed. The results show that before peak stress, the volume fractal dimension of pore-fracture is linear with axial stress and strain, that porosity of coal increases with the increases of effective stress, and the permeability increases first slowly and then sharply, that the permeability increases with the increase of ln (1/ r) at the same stress point, and that solutions of both the damage constitutive model and the permeability model of coal conform closely with the experimental data. © 2019 China Safety Science Journal. All rights reserved.

Language: zh