Timber Bridge Inspection Using UAV

Unmanned aerial vehicle (UAV)-enabled bridge inspection has gained more interest over recent years among bridge owners, researchers, and stakeholders due to inefficiency and high cost of conventional access inspection techniques. A large number of deteriorating bridges can be efficiently inspected using UAVs equipped with various sensors. In fact, some departments of transportation (DOTs) (e.g., Minnesota DOT) in cooperation with research institutions have investigated the effectiveness of UAVs as a cost-efficient bridge inspection alternative. Based on the findings from the projects done by the DOTs in their states, this paper is intended to demonstrate the effectiveness of a UAV by inspecting a timber arch bridge in the State of South Dakota (SD). The bridge inspection using UAV was completed based on multiple analyses of high-resolution images and videos recorded from the UAV. Further, the use of a pixel-based damage quantification methodology provided a quantifiable value for the observed damage. The visual results obtained from the UAV-based bridge inspection were compared to those from the past inspection reports from SDDOT. The comparison of results demonstrated the ability of the UAV to identify damage. It is expected that this emerging technology will supplement routine bridge inspections conducted with conventional methods.