Updating reliability of steel miter gates on locks and dams using visual inspection results

As both reliability analyses and systematic inspection programs for the world’s infrastructure gain increased usage and prominence, it becomes more important to use the information from routine visual inspections to update lifetime reliability assessments and resulting life-cycle inspection/repair strategies. The Army Corps of Engineers currently uses reliability analyses to economically justify the major rehabilitation of navigation structures. This paper illustrates how the Condition Index visual inspections for locks and dams can be modified and used to update the reliability analysis of a steel miter gate. The miter gates on two existing locks and dams along the Mississippi River are used as examples for corrosion and fatigue deterioration. The approach used is applicable to any structure where the inspection condition states are quantitative and a model exists to relate visual inspection results to the actual deterioration state of the structure.