Modelling shakedown demand on rockbolts

Authors: Rigby, A; Malovichko, D; Kaiser, PK Download Paper

DOI https://doi.org/10.36487/ACG_repo/2625_44

Cite As:
Rigby, A, Malovichko, D & Kaiser, PK 2026, 'Modelling shakedown demand on rockbolts', in D Cumming-Potvin & J Wesseloo (eds), Ground Support 2026: Proceedings of the 11th International Conference on Ground Support in Mining, Australian Centre for Geomechanics, Perth, pp. 1-13, https://doi.org/10.36487/ACG_repo/2625_44



Abstract:
Shaking due to remote seismic events places a demand on ground support that can result in damage or failure of support elements. This demand cannot be fully quantified by any single ground-motion intensity measure such as peak ground velocity/peak particle velocity (PGV/PPV). An alternative approach, inspired by practices in earthquake engineering, is to simulate shakedown loading using the simple zero-dimensional (0D) model proposed by Malovichko & Kaiser (2020). In this 0D model, shaking of a block of rock supported by a bolt is represented as shaking of a mass connected to the surrounding rock by an elastoplastic spring (representing the bolt) and a viscous damper (representing energy dissipation to sources such as friction). Four verification cases are presented that compare results from a 0D model with those determined from two-dimensional dynamic modelling of shakedown loading using the finite-discrete element method (FDEM). These demonstrate that 0D models can be used to estimate bolt deformation for near-ideal cases. In addition to these verification cases, results are presented from a more realistic FDEM simulation where a circular tunnel with a pre-existing notch of stress-fractured rock in the back is subjected to strong shaking. While a 0D model cannot capture the full complexity of the notch’s movement and the corresponding bolt loading, it is demonstrated that important characteristics can be reproduced such as the final bolt deformation. Lastly, it is shown that 0D models can be used to develop simplified parameterisations of shakedown demand. This is of practical relevance for support design because it allows for shakedown analysis without explicit simulation of the tunnel-failure process.

Keywords: shakedown demand, numerical modelling, rockburst hazard

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