Assessing rockfall retention strategies using field-calibrated rockfall modelling

Authors: Restrepo, J; McNabb, JC; Potter, JJ; Warren, S; Ryan, T; Luxbacher, K Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2535_10

Cite As:
Restrepo, J, McNabb, JC, Potter, JJ, Warren, S, Ryan, T & Luxbacher, K 2025, 'Assessing rockfall retention strategies using field-calibrated rockfall modelling', in JJ Potter & J Wesseloo (eds), SSIM 2025: Fourth International Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2535_10



Abstract:
This study extends a previously calibrated rockfall model developed using field data from full-scale tests on a single bench. The original model, based on RocFall2 simulations and using six-inch synthetic concrete blocks, was calibrated to match observed behaviour. It achieved 90% rock retention within 10.9 m from the bench toe. When the Modified Ritchie Criterion was applied, the resulting 9.4 m bench width produced approximately 80% retention at the first bench, with full containment achieved by the sixth. In this second phase, the calibrated model was used to evaluate the effectiveness of integrating energyabsorbing barriers with reduced-width catch benches. A total of 24 two-dimensional simulations were conducted, combining four bench widths, three barrier setback distances, and two barrier heights. Each simulation recorded the percentage of rocks retained before reaching the barrier, intercepted by the barrier, and those that passed beyond the system. The results show that optimised barrier configurations can compensate for reduced bench width. In several scenarios with bench widths as narrow as 5.2 m, near-complete rockfall containment was achieved. Barriers placed closer to the bench crest and constructed at greater heights consistently improved performance. The best-performing setups retained over 99% of rocks through a combination of effective bench designs and barrier placements. In addition to improving safety, the use of barriers provides increased flexibility in pit design. By enabling steeper slopes and narrower benches without compromising rockfall control, barrier systems allow deeper ore recovery and improved overall pit economics. This study offers quantitative evidence supporting the application of barriers as an efficient and practical solution for rockfall mitigation in open pit mines.

Keywords: rockfall, barriers, catch benches, retention performance, modelling simulation

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