Case Studies

Pillar performance – confined pillars

Understanding confined pillar performance under high stress

An anonymised technical case study demonstrating how site observations, model calibration and practical geotechnical judgement can support better mining decisions.

Problem

Pillar behaviour needed to be understood and validated under a high-stress mining sequence. The challenge was to assess how confined pillars performed, how damage developed, and what stress conditions should inform future pillar design and extraction planning.

Scope

JM Geomechanics used modelling, back analysis and available core drilling/logging observations to compare predicted pillar damage with observed performance. The work helped validate the stress levels associated with different stages of rock mass damage.

Technical approach

Review pillar geometry, confinement conditions and mining sequence context.
Compare modelled stress conditions with observed pillar damage and core logging evidence.
Back-analyse damage mechanisms and evaluate confined versus unconfined performance.
Use calibrated observations to inform forward modelling and future design thresholds.
Provide practical design inputs for pillar dimensions, sequence and support strategy.

Outcome

Improved understanding of pillar damage development and confinement benefits.
Optimise mining block dimensions and resource recovery.
Support for optimised pillar dimensions and extraction sequence under high-stress conditions.
Design inputs for ground support and access controls around areas of changing stress.
A stronger basis for forecasting rock mass response in future mining blocks.

Related services

Advanced 3D non-linear numerical modelling
Ground support design
Mine planning and design
Pillar design and stope stability assessment
Geotechnical audits, reviews and hazard management

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Pillar performance – confined pillars

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