Abstract
Mechanical scaling is an essential component of the mining cycle in large underground excavation operations. The process is an inherent component of ground control practices towards creating and maintaining safe active workings in underground mines. The nature of rock scaling requires intense mechanical efforts delivered by heavy machinery through a slow and repetitive process. There lies valuable consideration for operators to reduce the efforts required for mechanical scaling. This can typically be achieved by modifying key steps of the mining processes (e.g. blasting pattern, initiation sequence and timing, reduce overbreak). The impact of such changes in these processes are hard to translate directly at scaling efforts given the subjective nature of assessing the quality and overall roughness of a rock surface. An objective rating is proposed to quantify the condition of rock surfaces in terms of roughness and associated expected effort with respect to the mechanical scaling process. The rating is derived from automated processing of point clouds captured using mass data collection tools (LiDAR in this case). The rating expands from the basic definition of point cloud surface roughness by comparing the overall roughness measurements at different radius of measurements. A series of examples from underground room and pillar mines is presented as perspective of reference to define a site specific baseline. The proposed rating effectively provides operations with an objective way to quantify excavation conditions, assess changes within mining process, and define expected outcome from systematic mechanical scaling. Special considerations are given to the size of the tool used and size of the excavation span.