In RS2 you can model a jointed rock mass in two ways, as a continuum and as a discontinuum.
When modeling a jointed rock mass as a continuum, you require the intact strength and the scaling relationships to account for the joints. This is commonly done with the Generalized Hoek-Brown strength criterion.
When modeling a rock mass as a discontinuum, we use Goodman joint elements. This method is described in "The Practical Modelling of Discontinuous Rock Masses with Finite Element Analysis".
There are also numerous other papers on the modeling of jointed rock masses using RS2. See the link below: