Validation of Diametrical Core Deformation Technique for Mining-Induced Stress Estimation: A Case Study

In a recent work, the authors demonstrated the merits of the diametrical core deformation technique (DCDT) for stress determination at an excavation face. An analytical model was developed and verified with laboratory tests. This paper aims to validate the DCDT in the field using a well-documented case study from a Canadian underground mine. Rock cores are extracted from the floor of a footwall drive 1000 m below surface for the purpose of estimating stress magnitude and orientation. The DCDT is applied to the extracted cores and the state of stress in the drift floor is estimated. On the other hand, a mine wide FLAC3D model was developed using the geomechanical data and in situ stress regime obtained from a previous study. The model is a pared-down version of a comprehensive FLAC3D mine wide model that simulates past mine-and-fill sequence and was calibrated with various burst criteria and recorded mining-induced seismic events. A comparison of FLAC3D and DCDT in terms of floor stress estimates and orientation shows good agreement. The DCDT could be used as a ground control tool to help detect stress-related ground control issues. Extraction of rock cores from a drift floor 1000 m below surface for the purpose of stress estimation.Application of diametrical core deformation technique (DCDT) to estimate the biaxial state of stress-magnitude and orientation-in the floor.Development of a mine-wide 3D numerical model using geomechanical data and in situ stress regime.Validation of DCDT by comparison of stress orientation and magnitude estimates with calibrated numerical model. The comparison shows good agreement.