Problem Definition: One of our major clients faced challenges in one particular pit of a large coal mine with geotechnical issues in the highwall, resulting in a need to relocate an access ramp from one end of the pit to the other whilst still maintaining ROM coal uncover.
Approach: Geotechnical investigations led the project team to instigate a transition to a full-strip offset, however this geotechnically sound solution placed pressure on the schedule in this strip. Xenith used Earth Technology’s 3d-DigPlus with its new Automated Dragline module to investigate a range of options for maintaining coal uncovery whilst transitioning the pit towards an offset configuration. With the ability to quickly run different scenarios through 3d-DigPlus, the Xenith team were able to arrive at and model a solution involving bulk dozer assist, a double elevated (“pullback”) bench and also cutting in a new, lowwall ramp. As well as proving the concept and design, the site mine scheduling staff were provided with accurate physical quantities that were incorporated into the schedule for the entire mine.
Results: The key results were:
1. The proposed plan was safe from a geotechnical standpoint, as it enabled transition towards a full strip offset configuration;
2. The mine plan was able to show the required uncovery of ROM coal and stripping cost, so key client stakeholders were able to approve the plan;
3. The physical activity in the pit closely followed the plan modelled in 3d-DigPlus, due to the truly 3-dimensional nature of 3d-DigPlus modelling. The outputs were invaluable in explaining the plan to various site stakeholders including operators.