Bridge inspection using UAVs and selfie sticks after the 2024 Noto Peninsula earthquake

Post-earthquake bridge inspections are often hindered by the inaccessibility of scaffolding and inspection vehicles, particularly when urgent assessments are required to ensure structural safety and usability. Following the 2024 Noto Peninsula earthquake, this study explored the use of unmanned aerial vehicle (UAV) and selfie sticks equipped with cameras as practical alternatives for close-up inspections of road bridge components, such as bearings and piers. Pre-verification was conducted to clarify the conditions—especially camera-to-target distance and lighting—under which deformations can be reliably detected in photographs. These findings were applied to field inspections of multiple bridges in the affected region. Case studies demonstrated that UAVs were effective in capturing overall deformation in inaccessible areas, while selfie sticks provided high-resolution close-ups in situations where UAVs faced regulatory or environmental constraints. The research highlighted both the potential and limitations of these methods: although many types of deformation could be reliably recorded, certain stress conditions and tactile information remained unattainable. Overall, the study proposes a framework for combining UAVs and selfie sticks with conventional hands-on methods, ensuring reliable and efficient inspections without overlooking critical damage during post-earthquake recovery.