Concept Feasibility and Predicted Behavior of Mining a Rock Tower with Drill-and-Blast Undermining Using Dynamic Three-Dimensional Discontinuum Numerical Models

Abousleiman R.; Contreras C.I.; Cremeens J.; Worsey T.; Rouse N. · 58th US Rock Mechanics / Geomechanics Symposium 2024, ARMA 2024 (2024) · DOI: 10.56952/arma-2024-0591

Resumen

The safety and efficacy of a proposed novel mining method - felling a mineralized rock tower away from an adjacent river and towards an existing open pit using a wedge-shaped “key-cut” blast pattern and post-split hinge - was analyzed by integrating site-specific and site-adjacent data to develop a into a dynamic three-dimensional discrete element method numerical model. These data included historic laboratory testing and geomechanical core logging from the adjacent open pit, Lidar scans and geomechanical spot mapping of the rock tower, local signature blast seismic data, and proposed blast-pattern. Static and dynamic model stages were run to assess the pre-blast, syn-blast, and post-blast deformation of the mineralized rock tower. Model sensitivities to mesh size, dynamic time-step, block size, and joint strength were assessed. Ultimately, model results indicated that the proposed mining method would likely result in 97 percent retention of the blasted material within the existing open-pit, and only 3 percent of material would be cast towards the adjacent river. Copyright 2024 ARMA, American Rock Mechanics Association.