Medinac, F & Esmaeili, K 2020, 'Integrating unmanned aerial vehicle photogrammetry in design
compliance audits and structural modelling of pit walls', in PM Dight (ed.), Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 1439-1454, https://doi.org/10.36487/ACG_repo/2025_99
Existing field data collection methods for pit slope assessment are manual, time consuming, and can expose technical manpower in hazardous conditions. Advances in unmanned aerial vehicles (UAVs) technology allows collecting photogrammetry data of pit slopes. This aerial approach is fast, on demand and can improve the spatial and temporal resolution of the collected data. The collected data can be used to generate digital elevation models (DEMs) and point clouds to assess the bench face angle and catch benches. Furthermore, virtual mapping can be used to collect detailed structural data.
This study presents the application of UAV technology to collect data at a pit wall, in Nevada, USA. A DEM is generated to conduct a design compliance audit of the pit slope. The aerial photogrammetry data is used to generate a point cloud of the slope for virtual structural mapping. The structural mapping data is integrated with the surveyed pit slope geometry to generate a conditioned discrete fracture network (DFN) model. The discontinuities mapped on the slope surface are replicated in the DFN model, while behind the wall, a constrained stochastic model is used to describe the structural complexity of the rock mass. This combined deterministic-stochastic DFN model is used to conduct a kinematic stability analysis of the pit slope. The results are compared to the field observations of slope failure.
Keywords: UAVs, conditioned DFN, structural mapping, design compliance, open pit
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