DEM modelling of a jointed rock beam with emphasis on interface properties

This paper compares analyses performed via the distinct element method (DEM), employing rigid blocks and compliant joints, with results using finite-difference software (FLAC) obtained previously by other researchers. The paper then examines the capability of the rigid-block DEM at modelling joints realistically, with emphasis on the moment transfer between blocks. The line of thrust from this analysis was found to fit well with the well-established uniform catenary curve and the parabola, which has been used extensively in the rock engineering literature. This is an important verification exercise that is still lacking in the literature, especially for the rigid-block DEM. Finally, a comparison is made between the DEM and experimental work carried out previously by other researchers. The previously reported laboratory data were reinterpreted to derive more accurate contact laws in both normal and shear directions. A strain hardening or continuously yielding model was adopted in the latter. The calibration approach is demonstrated. The numerical findings suggest that improved predictions of beam deflections can be obtained and the predicted horizontal thrusts are comparable to the results obtained by FLAC.