Understanding the use of a continuum joint model for the analysis of an excavated drift

The response of an underground excavation in a geostatic stress field is simulated using a continuum representation of a jointed rock mass which averages the effects of individual joints with the matrix rock. To understand the rock mass response predicted by this model, the analysis is compared to predictions from an alternate model which uses explicit representations of the joints near the drift. The continuum model predicts joint response that is much greater than realized using explicitly-modeled joints. Certain structural effects of the intact rock between discrete joints near the drift are not well represented by the continuum model; this is primarily a local effect