A hybrid empirical-numerical framework for pillar stability and reinforcement in deep underground marble mines: a case study

Document Type : Research Paper

Authors

Department of Mining, National Institute of Technology Karnataka, Surathkal, India.

10.22059/ijmge.2026.393790.595241

Abstract

This study developed a hybrid empirical-numerical framework to enhance pillar stability and reinforcement in deep underground marble mines, addressing the challenges posed by increasing depths where traditional methods falter. The purpose was to create a reliable, efficient tool for assessing and optimizing pillar stability, ensuring safety at depths up to 30 meters. The methodology integrated empirical calculations, using the Obert and Duvall (1967) method, with FLAC3D numerical simulations, employing a depth-dependent weighting system (α) to balance simplicity and precision. Data from seven pillars (P1–P7) was preprocessed, analyzed, and optimized through width adjustments (e.g., P1 from 30 m to 60 m) and rock bolt reinforcement (1.8 m spacing). Findings revealed a decline in hybrid Factor of Safety (FOShybrid) from 3.59 at 5.5 m to 1.23 at 30 m pre-optimization, rising to 2.18 post-optimization, meeting the safety threshold 2.0. Validation against empirical (e.g., 3.616 at 5.5 m) and numerical (e.g., 1.95 for P6 at 21.5 m) FOS values, with R2 > 0.95 And CV < 15%, confirmed the framework’s accuracy. This hybrid approach significantly improved safety and efficiency, offering a scalable solution for deep mining. Future research could extend it to other rock types or incorporate real-time monitoring, enhancing its adaptability and impact.

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References

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International Journal of Mining and Geo-Engineering
Volume 60, Issue 1
March 2026
Pages 25-33

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