Keynote contribution

The importance of rock engineering for deep open pit slopes: Some considerations

Reşat Ulusay

Proceedings
EUROCK 2026
Pages
97-130
Submitted
1 June 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

When compared to underground mining, open pit mining is a more cost-effective mining method allowing high grade of mechanization and large production volumes. Much more need due to the exponential growth in the world population with easily accessible mineral resources becoming more scarce, increasing commodity prices, and improved production capabilities, leaded to much deeper and larger open pit slopes than have previously been considered and implemented. Therefore, particularly in the last few decades, depths of open pits approached and exceeded 1000 m. At these increased depths the risk of slope failure becomes greater, dependent upon the imposed design, and makes engineers question whether the analytical assumptions previously used on lesser slope heights are still valid. Formation of slope damage features, such as brittle fracture, rock mass dilation and bulging, are the main factors causing deformation of deep open pits and high natural rock slopes. In addition, strength of slope forming rock masses and discontinuities is reduced by the progressive accumulation of slope damage and cause a decrease in slope stability. In this keynote; differences and similarities between the stability of “deep-large” and “classical (shallower)” open pit slopes are discussed in terms of the main factors controlling slope stability such as rock type, discontinuities, effect of degradation, rock damage, hydrogeological conditions, rock mass strength, geotechnical model, effects of in-situ stresses and earthquakes, and importance of movement monitoring based on the recent practice and using some examples selected from practice.

Contributors

Authors

  1. Reşat Ulusay Hacettepe University, Turkiye ORCID 0000-0003-1930-7611

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