Slope Stability Assessments of Reservoir Embankments Using Uncrewed Aerial Vehicle (UAV) Datasets

Dam embankments are often built with earthen materials as a cost-effective solution to retain vast bodies of water and facilitate the channelization of water flow to meet the supply demands and safeguard the adjacent communities from flooding. The above characteristics deem these assets critical in nature and require frequent monitoring to prevent catastrophic failures. Even though conventional routine inspection practices are widely implemented across the world to monitor and manage these vast assets, they seem to be laborious and time-intensive. Further, only a few data points are captured and interpolated to provide a representative idea of the existing conditions. The in-service embankments undergo change in their surface profile due to the effect of loads, moisture, and weathering. In this study, an uncrewed aerial vehicle (UAV) was used to monitor and build a 3D model of the reservoir embankment. Drone-based photogrammetry has limitations in generating surfaces underneath the water surface. The 3D model from UAV datasets was augmented with extruded planar surfaces to represent a comprehensive model of the reservoir embankment. Two-dimensional (2D) and three-dimensional (3D) analyses were conducted on the embankment slope. Typical practice is to consider a 2D section or, in some cases, an extruded 3D model for conducting slope stability analysis. Interesting observations were made by comparing those results with the safety factor of a whole reservoir embankment model developed with the help of UAV datasets. Overall, the results highlighted the need for using data collection tools like UAVs to obtain a comprehensive 3D model for evaluating the stability of embankment slopes.