STUDY ON PERMEABILITY EVOLUTION IN FAILURE PROCESS OF INHOMOGENEOUS ROCK
非均匀岩石破裂过程渗透率演化规律研究

The phenomena of progressive failure leading to the collapse of the rocks can be simulated well by author-developed software F-RFPA2D. The simulated permeability variation in stressed rocks agrees well with the experimentally obtained results. Numerical results demonstrate that the trend and magnitude of the permeability variation are controlled by the stress and the damage evolution developed in rocks. The stress induced evolution of flow properties,and the regions of both diminished and enhanced flow depend on whether the rock is in the linear-elastic,nonlinear,or post-failure portions of the stress-strain curve. In elastic deformation region,rock permeability reduces when the rock is compacted. The decrease rate of the permeability starts to slow down or gradually increases again when micro fractures begin to nucleate. Dramatic permeability increment occurs as soon as the macro fracture forms in the rock.