Difficulties in relation to rock joints often make some troubles during the construction of underground openings in a rock mass. The behavior of the rock mass highly depends on the mechanical properties of discontinuity. Thus the rock joints must be considered in the analysis of underground openings in the rock mass in order to properly predict the behavior of a jointed rock mass.
An appropriate constitutive equation for the discontinuity, taking into account of some factors such as, roughness, dilatancy, aperture, wall strength, filling material and scale effect, is selected. A finite element analysis program for the jointed rock mass is developed. For a joint normal behavior, the hyperbolic model suggested by Goodman is used and, for a joint shear behavior JRC-JCS model proposed by Barton and Bandis is selected. The relationship between stress and strain of intact rock is presumed to be elastic. The joint element model developed by Goodman, Taylor and Brekke is used for describing the discontinuity behavior.
For an example of double layered mine roof, results obtained from the developed program agree well with those of Stephansson's beam theory. Finally, a full-scale numerical example is analyzed to investigate the effects of discontinuity on the behavior of rock cavern.
