Authors: Marulanda, Y; Vallejos, JA

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This paper is hosted with the kind permission of the Universidad de Chile, Eighth International Conference & Exhibition on Mass Mining, 2020.


DOI https://doi.org/10.36487/ACG_repo/2063_80

Cite As:
Marulanda, Y & Vallejos, JA 2020, 'Explicit numerical modelling of dynamic reinforcement', in R Castro, F Báez & K Suzuki (eds), MassMin 2020: Proceedings of the Eighth International Conference & Exhibition on Mass Mining, University of Chile, Santiago, pp. 1101-1113, https://doi.org/10.36487/ACG_repo/2063_80

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Abstract:
The widespread preference for the use of rockbolts to provide adequate rock stability in underground openings calls for a better understanding of the response of these reinforcement elements. Although it is widely accepted that fully-grouted rockbolts provide better stability in areas with high ground stress conditions, we know little about the response of these elements, especially under dynamic loading conditions. Numerical modelling of dynamic testing for reinforcement, using the FLAC3D code, was therefore conducted to study the behaviour of fully-grouted threadbar bolts under dynamic loading conditions. In order to obtain results that represent the real response of the reinforcement elements, an explicit model was calibrated to the laboratory behaviour of a series of fully-grouted threadbars, commonly used as reinforcement in underground excavations in Chile, tested under dynamic loading conditions using an impact test. Model calibration focused on matching the different constitutive responses of the main model components: grout, bolt and confinement. Modelling results are presented in terms of loading stages of the force displacement curve, including the initial elastic response, plastic behaviour and bolt energy absorption capacity. Finally, the study addresses the choice of input parameters required for a realistic simulation of the response of fully-grouted threadbar bolts.

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