AN ASSESSMENT OF POINT CLOUD DATA ACQUISITION TECHNIQUES FOR AGGREGATE STOCKPILES AND VOLUMETRIC SURVEYS

Abstract. Stockpiling aggregate materials is a common practice within the construction industry and with the demand for aggregates rapidly increasing, stockpile owners have taken a greater interest in the effective determination of volumes of inventory to optimize profit and limit waste. Historically, traditional stockpile measurement techniques were inaccurate but with the increase in demand, a higher quality and more reliable assessment of resources is necessary.

The evolution of point cloud measurement and mapping technology, such as UAV and Terrestrial Laser Scanning (TLS), now means these techniques can be utilized for stockpile measurements. While some of the advantages over traditional techniques have been well documented, there is still a need to ascertain which of these methods is more applicable for volumetric surveys of different types of aggregate stockpiles.

This study involved data collection and analysis from TLS and UAV photogrammetry for volumetric surveys and comparisons with Total Station (TS) measurement of the stockpiles for sharp sand, coarse (gravel) and finer aggregates.

The research suggested that TS surveys could only be effectively utilized on sharp sand and coarse aggregates and was impractical for finer aggregates, and their results produced a general under-reporting of stockpile volumes. TLS and UAV provide non-contact collection with increased accuracy. There are differences in accuracy and appropriateness dependent on the aggregate type. It was observed that the TLS outperformed the TS approach whereas UAV demonstrated promise particularly at a lower altitude with greater overlap.

Additional recommendations are shared to potentially improve productivity and inventory maintenance for Stockpiling Operations.