Hydraulic steel structures (HSS) are subject to periodic inspections, intended to document defects, inform dam safety, and to improve overall asset management of dams. Inspections typically consist of visual or non-destructive evaluation (NDE) techniques to identify deterioration and significant findings. For the Grand River Dam Authority 2023 Inspection of the (17) Kerr Dam Tainter gates, adoption of the draft US Army Corps of Engineers (USACE) – Inventory, Appraisal and Reporting Requirements for Hydraulic Steel Structures was piloted. Quantification and severity of inspected defects followed the five USACE manual element level classifications: corrosion, corrosion protection system (CPS), cracking, damage, and seals, for all steel gate members and components. Data collection proceeded utilizing inspector field measurements, images, descriptions, and calibrated estimates with to-scale plansets. A comprehensive condition state assessment for all Tainter gates was successfully achieved. The first part of this paper will evaluate a proof-of-concept from inspection planning, documentation, and utilization of the inspection data.
Element level data collection can be more laborious in the inspection and documentation phase but the benefit comes from utilizing that data. Having good condition state data provides the opportunity to utilize data for dam safety, asset management, risk analyses, and even potentially capitalizing some HSS maintenance costs by using predictive deterioration models and associated optimized maintenance plans for service life extension. A consistent and uniform method of inspection may improve the consistency and accuracy of structural failure mode estimation in risk analysis and maintenance optimization, such that HSS service lifespans can be prolonged successfully and safely. The second part of the paper will give both the input and output of a maintenance and inspection optimization model for Kerr Dam spillway radial gates.
