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, Australian Centre for Geomechanics, Perth, pp. 191-200, https://doi.org/10.36487/ACG_repo/2205_11
The decreasing availability of surface and shallow orebodies has driven an increase in the need for deep mining methods. One such method is cave mining, which has many advantages over other mining methods; however, these mines require a higher grade of ground support. Additionally, as a cave mine’s production progresses, excavations are exposed to an increased likelihood of seismic events, which further emphasises the need for an effective ground support system design.
When designing ground support systems for cave mining, the rock plate plays an important role, particularly when considering dynamic ground support selection. In block caving mining operations, a rock plate that can withstand the stresses developed by the caving method is essential to ensure safety in the mine and access to drawpoints. Inappropriately selected rock-plates can collapse and push off the rockbolt head when exposed to high strata loads leaving the excavation not properly supported.
Recent years has seen a growth in testing methods to quantify the performance of new ground support components, allowing ground support suppliers to deliver products meeting the needs of high stress cave mining conditions. Laboratory dynamic testing apparatuses have provided the opportunity to quantify and qualify the performance of dynamic ground support elements, both as a system and as individual elements.
In order to improve product validation capabilities, and to better represent the loading scenarios experienced within caving mines, Sandvik developed a new laboratory dynamic test method that will be presented in this paper. This new test method provides dynamic loading conditions in a controlled laboratory setting, which compliments Sandvik’s in situ dynamic test rig. The new laboratory dynamic test apparatus was utilised in the development of a new dynamic rock plate, to better complement the consistent dynamic performance of the MDX bolt. The new rock plate, the X-Plate, was developed to optimise material, dynamic energy capacity and subsequentially static compression capacity. When compared to the existing Sandvik rock plate, the X-Plate showed improvements of more than 54% in dynamic capacity and 22% in static capacity. In addition to the performance improvements of the X-Plate, a material reduction has resulted in a sustainability gain of an estimated 1,300 t CO2 per year.
Keywords: dynamic ground support, rock plate, bearing plate, dynamic testing, lab testing, sustainability
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