Dual-porosity poroelastic approach to behaviour of porous media over a mining panel

A dual-porosity poroelastic model is presented with the emphasis on identifying the effect of interaction between fractures and porous matrix on the change in fluid pressure and solid deformation as a result of mining. In a case study the finite-element method is used to approximate the formulation of fluid flow and stress change in the fractured media and a quasi-steady-state leakage function is used to describe the transfer of fluid between the fractures and porous blocks. In comparison to a single-porosity poroelastic model the analysis reveals that the dual-porosity model generates larger deformation and produces a substantially different fluid pressure profile in the initial period. The poroelastic behaviour of the porous media is apparently affected by fluid exchange between the fracture phase and the porous matrix phase, resulting in a history of delayed pressure dissipation. The finding of the research is important to the study of the behaviour of fractured porous media during the mining process.