110 7.1 Interpretation of Results in a System-Level Risk Context The results presented in Chapters 3 and 4 confirm that In-Pit Tailings Storage Facilities (InPit TSFs) provide a structural modification of the tailings management system, fundamentally altering its risk profile. Unlike conventional surface TSFs—where risk mitigation is largely achieved through incremental improvements in embankment design and operational controls—In-Pit TSFs reduce risk at its source by modifying geometry, energy storage, and containment philosophy. The comparative performance assessment demonstrates that the most significant risk reduction is associated with the elimination of elevated dams and the substantial decrease in stored potential energy. This finding is consistent with energy-based risk frameworks, which identify elevation and water retention as dominant contributors to catastrophic tailings failures (Davies & Martin, 2009; Morgenstern et al., 2016). Importantly, the reduced consequences of failure ( ) observed for In-Pit TSFs imply that even under adverse scenarios, the potential impacts remain localized and manageable, thereby improving overall system resilience. 7.2 Engineering Trade-Offs and Design Sensitivities While In-Pit TSFs offer clear advantages, their performance is sensitive to several key engineering variables. Hydrogeological conditions, in particular, play a critical role in determining long-term containment behavior. The maintenance of inward-directed hydraulic gradients is essential; failure to control internal water levels may compromise environmental performance. Similarly, pit slope geometry and rock mass quality govern geomechanical stability. Although competent rock masses provide robust confinement, conservative acceptance criteria are required due to the permanent nature of tailings storage and the limited feasibility of large-scale remediation post-closure. These trade-offs highlight that In-Pit TSFs are not universally applicable solutions, but rather context-dependent systems that require rigorous screening, conservative design assumptions, and continuous performance verification. 7.3 Implications for Sustainable Mining and Closure Planning From a sustainability perspective, In-Pit TSFs offer a rare convergence of operational efficiency, risk reduction, and closure optimization. By repurposing exhausted pits, mining operations reduce land disturbance, minimize long-term liabilities, and integrate closure objectives directly into operational decision-making. This approach aligns strongly with contemporary definitions of sustainable mining, which emphasize the minimization of longterm environmental and social risks rather than reliance on perpetual active management. In this sense, In-Pit TSFs represent not only a technical solution but also a strategic shift in how tailings management is conceptualized within the mine life cycle. 8. CONCLUSIONS In-Pit Tailings Storage Facilities represent a transformative approach to tailings management in open-pit mining. By utilizing exhausted pits as tailings repositories, mining operations
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