The mining industry increasingly requires robust and accurate pore pressure representation in slope stability evaluations. This need is evident in the growing number of operations employing pore pressure monitoring systems and numerical groundwater models. These real-world datasets create opportunities to verify the reliability and applicability of groundwater numerical model results against site-specific data.
A methodology for assessing the reliability of pore pressure models in slope stability evaluations was tested at two mine sites: Compañia Minera Antapaccay (CMA) copper mine in Peru, and the Pueblo Viejo Dominicana Corp (PVDC) gold mine in the Dominican Republic. Both sites presented have mature pore pressure models, with extensive hydrogeological and monitoring data in FEFLOW and MINEDW software, respectively.
The proposed methodology involves a three-step approach: evaluating groundwater construction and architecture, categorizing calibration behavior and residuals , and assessing geotechnical sensitivity to pore pressure. Finally, the methodology assigns pore pressure reliability scores to modeling outputs that are based on hydraulic head and trend categories and weighted by local-scale geomechanical importance. These scores guide the use and understanding of pore pressure outputs in geomechanical models.
For the case studies at the CMA and PVDC in question, results showed that both models had questionable elements but were not invalid. CMA exhibited larger residuals and error percentages than PVDC, highlighting the importance of site-specific geotechnical requirements. The methodology’s advantage lies in its project-specific approach, enabling rapid quantification and adjustment of pore pressure reliability volumes as guidance for slope stability analyses.
The final product includes reliability volumes and maps, intended for use alongside other spatial analyses to ensure accurate slope stability assessments. This approach provides a systematic tool for evaluating pore pressure outputs, aiding in the identification of necessary corrections before geomechanical modeling.
