Updating the reliability of aging miter gates in the presence of corrosion and fatigue

Miter gate is a type of navigation lock gate which is used to allow the passage of inland navigation across different levels in a river system. Aging miter gates suffer from structural deterioration due to fatigue and corrosion resulting in a reduction of structural resistance, influencing the integrity and life cycle costs. Therefore, it is essential to re-assess our belief in structural safety and perform maintenance accordingly to optimize the operation and maintenance costs. This research presents an approach to update the reliability of aging miter gates in the presence of corrosion and fatigue. The failure probability calculated in the present paper is based on a probabilistic crack propagation analysis which considers the uncertainty in material properties, weld geometry, and fatigue loading. The time-dependent capacity of a miter gate is assessed including the effect of both corrosion growth rate and corrosion fatigue. The method is then applied to an example where the failure probability of a miter gate welded joint is updated based on inspection outcomes. The reliability updating approach presented here can be used for risk-based maintenance optimization of lock gates.