Vallejos, JA, Marambio, E, Marulanda, Y, Burgos, L & Gonzalez, C 2019, 'Progress in the numerical modelling of dynamic testing for reinforcement and retaining elements used in underground excavations', 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. 357-374, https://doi.org/10.36487/ACG_rep/1925_24_Marambio
(https://papers.acg.uwa.edu.au/p/1925_24_Marambio/)
Abstract: In the last century the expansion of mining into high stress environments, where there are rockburst events caused by energy release, have become especially interesting for mining engineers in terms of geomechanics. These phenomena have prompted changes in conventional designs, implying more research into how underground excavations absorb dynamic impacts.
Testing programs carried out globally by recognised institutions have provided guidelines for the development of new support systems in the last 30 years. Therefore, new reinforcement elements and retaining elements capable of both resisting dynamic loads and yielding in the process without failing have been introduced in order to ensure safety of underground excavations. However, the integration of these elements under dynamic loads is a research area recently under development.
The execution of these testing programs implies a high cost in time and validation, hence a limited number of these have been completed. Numerical modelling to represent the performance of the dynamic process and enhance laboratory testing has become increasingly necessary and relevant.
This paper summarises improvements in the numerical modelling of dynamic testing, developed by the University of Chile and supported by MIRARCO (Mining Innovation Rehabilitation and Applied Research Corporation), for elements that constitute rock support used in underground excavations. An update of the numerical modelling of dynamic testing for threadbar used as rock reinforcement is presented. As well as the work carried out to date in the development of a numerical model of dynamic tests for a mesh used as a surface retaining element is illustrated.

Keywords: dynamic testing, reinforcement, retaining, numerical modelling, rockburst, high stress, underground mining