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Primadiansyah, Avesiena Adrian

University of British Columbia

The demand for critical minerals continues to increase as the world shifts towards green energy solutions. This trend has compelled the mining industry to mine deeper as near-surface mineral deposits become depleted, exposing projects to higher-stress environments in more massive, brittle rock. Under high stresses, massive rock fails via stress fracturing, resulting in rock spalls that can detach from the excavation perimeter in a progressive, non-violent manner as spalling or suddenly and violently as strainbursting. These phenomena ultimately lead to bulking around the excavation that increases susceptibility to damage or failure of safety-critical rock support systems, creating risks for workers and costly interruptions in production. Deformation-based support design (DBSD) is a recent and innovative approach for designing support in highly stressed brittle rock, offering several advantages to address these challenges. However, the limited availability of purpose-focused field-based data and systematic procedures for effectively determining DBSD critical parameters often hinders its optimization, particularly in deep caving operations. This research provides a systematic procedure and recommendations to improve the justification and optimization of the DBSD approach using data from the PT Freeport Indonesia (PTFI) Deep Mill Level Zone (DMLZ) panel cave mine. The study introduces a systematic process that integrates stress fracturing and bulking monitoring techniques, leveraging field data to calibrate the critical parameters of the DBSD. A site-specific predictive function is proposed for estimating the depth of stress fracturing and the corresponding displacement based on the transient nature of the bulking factor across the extraction level footprint. Implementing this procedure into PTFI's DBSD tool effectively improves the design approach and forecasting of preventative support maintenance requirements, thereby promoting the integrity and reliability of the excavation.

Text

2024-03-04

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87520

Geological Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/