The Joint Empirical Model---an equivalent continuum model for jointed rock masses

The Joint Empirical Model is an equivalent continuum model for mechanical behavior of jointed rock masses that was developed for incorporation into computer programs based on the finite element method. The model is based on the fundamental assumption that the joints are contact discontinuities; i.e., the tractions supported by the joint are in equilibrium with the stresses in the adjacent rock. The mathematical description of joint response is based on empirical relations derived from laboratory and field experiments. The FORTRAN implementation solves for simultaneous equilibrium on as many as four joint sets. This report describes the empirical relations and mathematical development used in the model, the program structure, and the verification problems that were solved to ensure that the FORTRAN implementation of the model performs the intended functions. 20 refs., 22 figs., 7 tabs