Authors: Knox, G; Hadjigeorgiou, J

Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2465_26

Cite As:
Knox, G & Hadjigeorgiou, J 2024, 'Direct impact load tests on mechanical hybrid rockbolts', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, pp. 467-478, https://doi.org/10.36487/ACG_repo/2465_26

Download citation as:   ris   bibtex   endnote   text   Zotero


Abstract:
A mechanical hybrid rockbolt is comprised of a tendon mechanically anchored within a friction unit. The rockbolt is driven into the pre-drilled borehole using a percussive force and can be efficiently and effectively installed in conditions where the application of resin cartridges is either challenging or impractical. The potential for higher installation rates and quality in friable or fractured rock masses, compared to resin grouted rockbolts, has resulted in the use of mechanical hybrid rockbolts for both static and dynamic conditions. Mechanical hybrid rockbolts are installed using percussion techniques. On completion of the percussive drive cycle, a rotation is applied to the tendon to activate the mechanical anchor. The frictional resistance of the friction unit generates the reactive force against which the mechanical anchor is activated with the tendon mechanically coupled at the distal and proximal end. Currently, there are limited data on the performance of mechanical hybrid rockbolts under different loading conditions in a controlled environment. This paper presents the results of a series of tests on mechanical hybrid rockbolts under direct impact loading. Direct impact continuous tube tests are one of the tools used to understand the performance of rockbolts under seismic loads. They are typically used to simulate a strainburst event where the seismic load acts on the interface (face plate) between the surface support and the rock reinforcement element. These results complement earlier work by the authors that focused on quasi-static axial and shear tests.

Keywords: mechanical hybrid rockbolt, impact testing

References:
Andrews, PG 2019, ‘Ground support selection rationale: a Gold Fields perspective’, in J Hadjigeorgiou & M Hudyma (eds), Ground Support 2019: Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction, Australian Centre for Geomechanics, Perth, pp. 15–28,
ACG_rep/1925_0.02_Andrews
Darlington, B, Rataj, M, Balog, G & Barnett, D 2018, ‘Development of the MDX Bolt and in-situ dynamic testing at Telfer Gold Mine’, Rock Dynamics and Applications, CRC Press, Boca Raton.
Darlington, B, Vallati, O & Young, P 2023, ‘A comparison between laboratory and in situ dynamic testing on the MDX bolt’, in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 361–370, 
DSI Underground 2023, KINLOC Bolt, viewed 2 February 2023,
Evans, DW 2022, ‘Data cross validation for a newly commissioned dynamic drop test facility’, Proceedings of The Fifth Australasian Ground Control in Mining Conference Proceedings, The Australasian Institute of Mining and Metallurgy, Melbourne,
pp. 320–328.
Epiroc 2023, Vulcan Bolt, viewed 2 February 2023,
International Standards Organisation 2009, Metallic materials - Tensile Testing at room temperature (ISO6892), West Conshohocken.
Jager, AJ 1992, ‘Two now support units for control of rockburst damage’, Rock mining and underground construction, A.A. Balkema, Rotterdam, pp. 621–631.
Jennmar 2023, Mech Lok Bolt, viewed 2 February 2023,
Knox, G & Hadjigeorgiou, J 2022, ‘Influence of testing configuration on the performance of paddled energy-absorbing rockbolts under impact loading’, Rock Mechanics and Rock Engineering, vol. 55, pp. 5705–5721.
Knox, G & Hadjigeorgiou, J 2023, ‘Performance in shear of mechanical hybrid rockbolts’, in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 495–506,
Knox, G 2023, ‘Laboratory-based drop testing of rock reinforcement’, in J Wesseloo (ed.), Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 23–38, 
Li, C 2010, ‘A new energy-absorbing bolt for rock support in high stress rock masses’, International Journal of Rock Mechanics and Mining Sciences, vol. 47, no. 3, pp. 396–404.
Li, C, Hadjigeorgiou, B, Mikula, P, Knox, G, Darlington, B, Royer, R, Pytlik, A & Hosp, M 2021, ‘Performance of Identical Rockbolts Tested on Four Dynamic Testing Rigs Employing the Direct Impact Method’, Journal of Rock Mechanics and Geotechnical Engineering, vol. 13, issue 4, pp. 745–754.
Sandvik 2023, MDX Bolt, viewed 2 February 2023,
Simser, B, Andrieux, P, Mercier-Langevin, F, Parrott, T & Turcotte, P 2007, ‘Field behaviour and failure modes of modified conebolts at the Craig, LaRonde and Brunswick mines in Canada’, in Y Potvin, J Hadjigeorgiou & TR Stacey (eds), Challenges in Deep and High Stress Mining, Australian Centre for Geomechanics, Perth pp. 347–354.
Vallati, O, Darlington, B & Sandberg, L 2022, ‘Dynamic drop testing of Sandviks D47 and D39 MDX bolts at the Swerim’s testing facility’, Proceedings of The Fifth Australasian Ground Control in Mining Conference Proceedings, The Australasian Institute of Mining and Metallurgy, Melbourne, pp. 428–440.




© Copyright 2024, Australian Centre for Geomechanics (ACG), The University of Western Australia. All rights reserved.
View copyright/legal information
Please direct any queries or error reports to repository-acg@uwa.edu.au