Permeability of Fractured Media under Confining Pressure: A Simplified Model

An elastic-plastic model was developed to describe the deformation and permeability of fractured rocks under confining pressure. Elastic and elastic-plastic contact models were used in the model to analyze the deformations of a representative element containing a single fracture under various confining pressures. The present work utilized elements from contact mechanics and viscous flows to derive an expression for permeability of fractured rocks under a range of confining pressures. The elastic-plastic model predictions for coal permeability under loading and unloading confining pressure were compared with the experimental data. The new model exhibited trends similar to the data for the range of confining pressures used in the experiments. The model can be used to predict the permeability of other fractured media with different material properties.