Honggang Zhao

TL;DR: In this article, the effects of fracture geometry, water adsorption and stress conditions on the permeability evolution of coal as a function of stress are systematically studied, and the results indicate that permeability anisotropy is more pronounced in fractured coal than in intact coal.

TL;DR: In this article, the effects of water weakening, intermediate stress, and structural anisotropy on the mechanical properties and failure behavior of dry and water-saturated anisotropic coal samples subjected to different true-triaxial loading stresses were conducted.

TL;DR: In this article, the anisotropic characteristics of the effective stress coefficient for sandstone under different true triaxial stress and pore pressure conditions were investigated, and the results showed that effective stress coefficients exhibited anisotropy due to the different principal strains in three directions and the annessotropy of pore structure, and it is closely linked with the pore fluid flowing through highly compressible clay aggregates.

TL;DR: In this article, three different lateral stresses were loaded to perform biaxial compression experiments on sandstone specimens with a trapezoidal opening, and the results indicate that the high lateral stress accelerates the formation of localized damage around the trapezoid opening, which can effectively consume the elastic strain energy.

TL;DR: In this paper, backpropagation neural network (BPNN), genetic programming (GP), and multiple regression analysis were employed to construct prediction models of sandstone permeability based on the coupling effect of true triaxial stress field and pore pressure.