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Methodology Supporting Civil Works Implementation of Tainter Gate Trunnion Friction Structural Health Monitoring

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[Technical Report, Technical Note]

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PURPOSE The purpose of this Coastal and Hydraulics Engineering Technical Note CHETN is to provide guidance on the applicability of trunnion friction monitoring at navigation dams with Tainter gates. BACKGROUND The U.S. Army Corps of Engineers USACE, as part of its Civil Works mission, operates and maintains approximately 700 dams. These dams provide many U.S. benefits including flood protection, water supply, hydropower, recreation, fish and wildlife conservation, and inland waterway navigation capability. The USACE dam portfolio averages over 50 years of age, and over half of the USACE-managed dams have exceeded their design service life. Currently, available funding is less than that needed to fully repair the dam portfolio. It is crucial that USACE direct repair funding and efforts at the most critical infrastructure to maximize safety and national benefit. Structural health monitoring SHM techniques can be used to help identify opportunities for just-in-time maintenance and repair.A key component for many dams is spillway gates, which control the release of water from a dam. Tainter gate trunnions must be relatively free of friction, or the lifting of the gate may overstress, or fatigue, elements or connections within the end frames. Trunnion friction has been documented as the cause of a spillway gate failure at Folsom Dam in California in 1995. Spillway gate failure may lead to downstream flooding and loss of dam pool. Either of these consequences may cause significant loss of life, damage to public and private property, damage to ecosystems, loss of hydropower availability, loss of local benefits associated with the water reservoir, or loss of river navigability. It is very important for USACE to be aware of friction within the trunnion bearings with sufficient notice such that appropriate actions may be taken to prevent catastrophic failures.


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  • Civil Engineering

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[A, Approved For Public Release]