2026 Volume 5 Issue 1 Pages 328-332
To ensure the long-term stability of landslide-prone areas, maintaining the functionality of landslide countermeasures is crucial. However, drainage wells, one type of landslide countermeasures, may experience a decline in functionality over time due to deterioration. Entering the drainage wells structure for work poses risks such as oxygen deficiency, toxic gas poisoning, falls, and deterioration of access stairs, presenting challenges for safety management. To address these issues, an inspection method has been developed that involves lowering a camera into the drainage well to capture and assess the condition of the inner wall and drainage pipes. This method allows for safer and easier inspections compared to conventional approaches. In Ōita Prefecture, a 360-degree camera was used to film the inside of a drainage well. Still images were extracted from the video and stitched together to create a panoramic photograph, and a 3D model(Three dimensional point cloud data) was generated using Structure from Motion(SfM) analysis technology. The panoramic photograph enabled the identification of corrosion and deformation of the liner plates and clogging of the drainage pipes, while the 3D model allowed for the assessment of deformation within the well shaft. These techniques proved effective in evaluating the functionality of the facility.
