Performance testing of various dynamic bolting element designs

Authors: Evans, DW Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2465_28

Cite As:
Evans, DW 2024, 'Performance testing of various dynamic bolting element designs', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 491-502, https://doi.org/10.36487/ACG_repo/2465_28



Abstract:
The ability of ground support elements to take the demands of sudden and severe service loads continues as an increasing requirement for geotechnical application within the underground hard rock mining industry. Large amounts of energy can suddenly be released through the rock mass as stresses are redistributed – and at times violent ground movement can occur. Based upon the need to address such geotechnical demands, dynamic ground support remains an important area of continued study and research. While geotechnical design is the overarching discipline, the mechanical response of ground reinforcements is equally critical to understand and apply within this field. The requirement for this unique area of research is fundamentally driven by differences in mechanical performance that are observed under varying loading rates and scenarios. The mechanical response of ground support elements under rapid loading typically differs from the results of test work that is conducted at low loading rates. As such, performance assumptions that are based on low-speed mechanical test work may not be completely relevant within the context of a dynamic event. This paper provides an overview of a recently developed test rig for the dynamic testing of hard rock bolting elements. This rig has been used to explore the dynamic performance of a number of different classes of bolting elements and, further to this, to evaluate the performance of the anchoring and embedment media that is utilised in association with the bolting element. An overall summary of the test work is provided, covering mechanically anchored bolts, resin anchored bolts and cementitious grouted bolts. This appraisal clearly shows that bolt installations must operate as a complete system: the mechanical response of the bolting element is only proportionate to the anchoring strength of the embedment media.

Keywords: dynamic testing, drop test, rockburst, dynamic rock bolts

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