Keynote contribution

Understanding failure mechanisms to design and manage risks for surface and underground excavations

Neil Bar

Proceedings
EUROCK 2026
Pages
71-95
Submitted
20 June 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

Ground failures are a common aspect of rock slope and underground excavation design. Some ground failures are accepted and even economically attractive provided they are managed so that no personnel are at unacceptable risk. Too many failures impact on productivity and project costs.Larger scale ground failures are less tolerable due to their economic impacts, schedule delays and negative publicity, irrespective of how well they were managed. Poorly managed ground failures have been the cause of numerous fatalities in mining, tunnelling and construction industries. Failure mechanisms in surface and underground excavations are becoming more and more understood. With improvements in numerical modelling since the 2000s, it has become possible to replicate almost all complex failure mechanisms in numerical simulations. However, more often than not, this level of detail occurs only after a ground failure event has happened. Much of the predictive stability modelling that is undertaken during the design of a rock slope or underground excavation contains significant geological uncertainty, includes simplification when simulating potential geotechnical problems and does not consider all plausible failure mechanisms. For many projects, this design is static, and is not revisited after excavations commence and more engineering geological information becomes available. This paper focuses on the need for understanding failure mechanisms to effectively design surface and underground excavations and manage residual risks through a combination of a continuous improvement framework and critical control measures.

Contributors

Authors

  1. Neil Bar Gecko Geotechnics, Saint Vincent and the Grenadines ORCID 0000-0001-7948-2468

Index terms

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Works cited

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