Identifying Unfavourable Discontinuity Sets From UAV Point Cloud Data for Rock Slope Engineering

In assessing the slope stability of blocky rock masses, it is essential to identify discontinuities, their location dependent characteristics, and the kinematic failure modes they cause. As remote sensing technology has improved, advances have been made in using new forms of data for undertaking slope stability analysis. This research details the use of data obtained from UAV tilt photogrammetry, focusing on the extraction of 3D rock mass structure directly from a point cloud. A carbonate outcrop near Kaili in Southern China was studied, with a sub-vertical exposed face of approximately 70,000 m2 in area. 3D rock mass structure was extracted directly from the point cloud to allow discontinuity sets to be defined and characterised in terms of orientation, spacing, persistence and roughness using the program CloudCompare. Kinematic analyses were undertaken considering these parameters in order to determine potential mechanisms of failure.