Comprehensive Dam Condition Assessment, Inspection and Survey Services
ASI was subcontracted to provide underwater services using remote inspection technologies, bathymetric surveys, and two-dimensional (2D) sonar imaging at a hydroelectric facility. The objectives of this project were to conduct a general condition assessment of the power conduit, penstocks, and intake trash racks at the dam, as well as a bathymetric survey of the surrounding reservoir bed.
ASI conducted the external survey using a surface vessel to collect 2D imagery of the trash rack structure and high-resolution 3D multi-beam sonar data of the entire upstream toe and dam face. Additional imagery of the trash rack was collected using an ROV equipped with a high definition camera, imaging sonar, and profiling sonar.
For the internal power conduit and penstock inspections, an ROV was deployed equipped with cameras, imaging sonar, inertial navigation, and high-resolution multi-beam sonars. Along with the video and 2D sonar data, ASI assembled a 3D point cloud model of the entire tunnel. Ultrasonic thickness data was collected in the metal penstocks and reported accordingly.
The inspection data presented mapped elevations of the reservoir surrounding the dam and a detailed model of the dam face, intake structure, power conduit and penstocks, providing both an overview of the infrastructure’s condition as a whole and a detailed account of each critical area. Subsequently, this data was further combined with aerial lidar point cloud data to create a complete model of the asset above and below the waterline, internally and externally. The reported data, which included a written report, edited inspection video, video and sonar stills, bathymetric contour maps and 3D point cloud data, provide an accurate baseline for comparison to past or future inspections and is entirely repeatable to assist with monitoring and maintenance needs.