The Influence of Corrosion Fracture of Prestressed Reinforcement on the Behaviour of Large Aqueducts

As a critical hydraulic structure, the safety of large prestressed aqueducts is essential. This study employs distributed optical fiber sensing based on PPP-BOTDA to monitor deformation in concrete beams during prestressed steel reinforcement corrosion and fracture, with results validated by finite element analysis (FEA). Using a real aqueduct as a case study, the influence of corrosion and fracture in three-way prestressed reinforcement under both emptying and normal water supply conditions is investigated via numerical simulation. A distributed optical fiber sensing system is preliminarily proposed for continuous monitoring of prestressed reinforcement performance. Results indicate that when the sensing fiber is within 150 mm of the corroded reinforcement, strain monitoring data show significant changes, and fracture locations are accurately identified. Under emptying conditions, corrosion of a single longitudinal prestressed steel bar in the bottom plate has minimal impact on concrete surface strain, whereas under water supply conditions, longitudinal reinforcement corrosion has a more pronounced effect than transverse or vertical reinforcement corrosion.