MODELING STORAGE BEHAVIOR IN A FRACTURED ROCK MASS

A transient model was used to represent single borehole injection tests in fractured rock masses, on the basis of a three-dimensional stochastic description of the fracture network and of the mechanical behaviour of the fractures. The rock matrix remains impervious and storage occurs in the fractures, with a nonlinear compliance effect depending on both fluid pressure and normal closure stress acting on the joints. The aim of the study is to show how the shortest, weakly connected joints can be removed and replaced in the system by an equivalent parameter. These efforts can save computer time or enlarge the modelled rock volume. Moreover, this approach may be helpful in addressing the troublesome up-scaling problem in discontinuous media.