Two-scale modeling of jointed rock masses

Numerical modeling of the mechanical behavior of jointed rock masses is a difficult task as the discontinuities not only require special modeling consideration, but also require different treatments depending upon the scale of problem involved. A framework is proposed here that is based upon a meshed based partition of unity method, also known as the numerical manifold method. Specifically, the discontinuities posed by joints or faults are divided into two groups. The primary discontinuity set is the one with a wider spacing and dominates the kinematics of the system. It is modeled explicitly as physical discontinuities. The secondary discontinuity set, characterized by high density and small spacing, is modeled as an equivalent continuum by incorporating joint compliance and strength characteristics. Following the presentation of the formulation, two examples are also provided at the end to highlight the ease with which the proposed approach may be used in mechanical analysis of a complex jointed rock system.