CONSTRAINING NUMERICAL-MODELS WITH GEOMECHANICAL DATA AND MICROSEISMIC FAULT-PLANE SOLUTIONS

Geomechanical and seismic analyses are used to constrain interpretatio ns based on a 3-D boundary element model (BEM) for different stages of an excavation at depth. Mapping results indicate four dominant joint sets throughout the rock mass Fault-plane solutions defined two potent ial failure planes, one of which closely fits, in both strike and dip, the mapped Stratigraphic Bedding set. BEM calculated principal stress orientations compared well to the pressure, tension, and intermediate axes obtained from the fault-plane solutions. Ubiquitous joint analys es, with BEM derived shear/normal stresses for each joint set at the e vent locations, indicate that only the Stratigraphic Bedding met the d erived Barton-Bandis failure criteria Based on these correlations, it is suggested that an integrated approach with seismic and geomechanica l data can be used to constrain numerical stress analyses interpretati ons.