Geotechnical and operational risk management planning for a long ore pass

Jeanne Walls

doi:10.68732/f8900690a43fc700

Paper contribution

Geotechnical and operational risk management planning for a long ore pass

Jeanne Walls

DOI: https://doi.org/10.68732/f8900690a43fc700
Proceedings: EUROCK 2026
Pages: 225-230
Submitted: 28 January 2026
Accepted: 15 June 2026
Published: 12 August 2026

Summary

Abstract

The use of long ore passes for ore handling presents an appealing alternative to offset the energy burden and safety risks associated with trucking solutions for underground extraction. In particular, where orebody shape and infrastructure arrangement presents an opportunity to place and utilise a long ore pass, inclusion of a geotechnical and operational risk assessment during the planning stage becomes imperative to eliminate potential fatal flaws or severe impediments to the operation. Several recent studies have been concluded within the broader industry to review and benchmark geotechnical and operational risk management issues associated with the use of long (300-500 m) and ultra long (>500 m) ore passes; however, knowledge and data in the public domain specific to geotechnical and operational risk assessment for long ore passes remains limited. Specific questions that remain unanswered include the cumulative risk effect of known hazards – both geotechnical and operational – as a function of ore pass length, and strategies to successfully manage a long ore pass. This paper presents a single case study in which a detailed, albeit qualitative, risk management assessment was carried out to determine the feasibility for utilising a long ore pass in a caving operation. As an outcome of the risk assessment, decisions were enabled regarding planned risk mitigation interventions, ore pass maintenance and replacement strategy, and ore handling solutions required to ensure a feasible and sustainable operation. These included planned placement of a replacement pass, column height monitoring, the use of continuous column feed, water management, access points for hangup release, and a split pass system. Results of this case study may assist in expanding the current knowledge base, and solution management for similar industry challenges.

Contributors

Authors

Jeanne Walls AMC Consultants (Pty) Ltd, South Africa

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Full paper (PDF)Paper_22_Eurock_2026.pdf · 1.1 MB

Works cited

References

Bartlett P. (2020) Lessons learned in designing ore handling systems for kimberlite ore (internal report).
Bartlett P. (2022) Mining in Kimberlite (internal report).
Bunker KA, Campbell AD, O’Toole, D, Penney, A (2015) Guidelines for ore pass design in a sublevel cave mine. Design Methods in Underground Mining 2015. Perth: Australian Centre for Geomechanics.
Hadjigeorgiou JS (2013) The absence of strategy in ore pass planning, The Journal of The Southern African Institute of Mining and Metallurgy, vol 113, pp 795-801.
McCracken AS, Stacey TR (1989) Geotechnical Risk Assessment of Large Diameter Raise-bored Shafts. Shaft Engineering Conference (pp. 309-316). IMM.
Peck WA, Lee, MF (2008) Stability of Raise Bored Shafts in Australian Mines. 13th Australian Tunneling Conference. Melbourne.
Roberts MN (2011). Shaft Barrel and Station Support for the 10 m Diameter Service Shaft and the 7 m Diameter Production Shaft.TWP - De Beers.
Salmi EF, Phan T, Sellers EJ, Stacey TR (2024) A review on the geotechnical design and optimisation of ultra-long ore passes for deep mass mining. Journal of Environmental Earth Sciences, 83:301-
Stacey TR (2005). Setting the scene: rockpass accident statistics and general guidelines for the design of rockpasses. South African Institute of Mining and Metallurgy, vol 105, no 11, pp 745-752.
Walls EJ. (2019). Geotechnical data analysis to select a feasible method for development of a long axis, large diameter vertical ventilation shaft. Journal of the South African Institute of Mining and Metallurgy, 377-384
Wang J, Cuifeng D, YaPeng W (2021) Research on the Influencing Factors and Prediction Model of Impact Airflow in the Process of Unloading of an Ore Pass Based on a Coupled Computational Fluid Dynamics and Discrete Element Method. ACS Omega. 2021 Aug 31;6(36):23100-23109.

[1] Bartlett P. (2020) Lessons learned in designing ore handling systems for kimberlite ore (internal report).

[2] Bartlett P. (2022) Mining in Kimberlite (internal report).

[3] Bunker KA, Campbell AD, O’Toole, D, Penney, A (2015) Guidelines for ore pass design in a sublevel cave mine. Design Methods in Underground Mining 2015. Perth: Australian Centre for Geomechanics.

[4] Hadjigeorgiou JS (2013) The absence of strategy in ore pass planning, The Journal of The Southern African Institute of Mining and Metallurgy, vol 113, pp 795-801.

[5] McCracken AS, Stacey TR (1989) Geotechnical Risk Assessment of Large Diameter Raise-bored Shafts. Shaft Engineering Conference (pp. 309-316). IMM.

[6] Peck WA, Lee, MF (2008) Stability of Raise Bored Shafts in Australian Mines. 13th Australian Tunneling Conference. Melbourne.

[7] Roberts MN (2011). Shaft Barrel and Station Support for the 10 m Diameter Service Shaft and the 7 m Diameter Production Shaft.TWP - De Beers.

[8] Salmi EF, Phan T, Sellers EJ, Stacey TR (2024) A review on the geotechnical design and optimisation of ultra-long ore passes for deep mass mining. Journal of Environmental Earth Sciences, 83:301-

[9] Stacey TR (2005). Setting the scene: rockpass accident statistics and general guidelines for the design of rockpasses. South African Institute of Mining and Metallurgy, vol 105, no 11, pp 745-752.

[10] Walls EJ. (2019). Geotechnical data analysis to select a feasible method for development of a long axis, large diameter vertical ventilation shaft. Journal of the South African Institute of Mining and Metallurgy, 377-384

[11] Wang J, Cuifeng D, YaPeng W (2021) Research on the Influencing Factors and Prediction Model of Impact Airflow in the Process of Unloading of an Ore Pass Based on a Coupled Computational Fluid Dynamics and Discrete Element Method. ACS Omega. 2021 Aug 31;6(36):23100-23109.