Structural reinforcement of trunnion girder beams: application of prestressed buttresses

The trunnion girder plays a crucial role in supporting the forces generated by a reservoir’s hydrostatic pressure on the gates of controlled spillways. This paper presents a review of structural reinforcement techniques used to restore the capacity of these beams at a Brazilian dam, focusing on the solution of prestressed counterforts for structural reinforcement. The theoretical concepts, advantages, and challenges associated with post-installed prestressing, as well as its potential for application in highly aggressive environments, are discussed. The proposal aims to provide a robust and economically viable technical option for dam rehabilitation.