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Under normal marine conditions, in ordinary reinforced concrete piers that have not undergone long-term anti-corrosion treatment, the corrosion cycle of the core structure is approximately 15 years; after that, serious defects such as concrete cracking and exposed rebar occur, posing a threat to the structural safety. I. Differences in corrosion cycles under different operating conditions: In the absence of special anti-corrosion measures, the corrosion rate of ordinary steel in areas subject to wave splashing is approximately 0.3 mm per year; as a result, the effective service life of components with standard thicknesses is only 5–10 years, which is far below the required design lifespan. Conventional anti-corrosion methods, such as thickening the concrete protective layer and applying anti-corrosion coatings, can only delay corrosion; they usually become ineffective after 5 to 10 years, requiring frequent repairs. Complementary cathodic protection technology: Through cathodic protection methods using external current or sacrificial anodes, the effective service life of dock structures can be extended from 15 years to 30–50 years, thereby significantly reducing operation and maintenance costs. II. Key factors affecting the corrosion cycle: There are significant differences in corrosion intensity across different marine zones: corrosion is most severe in wave-splashed areas, followed by areas with tidal fluctuations and fully submerged areas, while the corrosion rate is relatively lower in areas covered with marine sediment. Environmental parameters such as oxygen content, salinity, temperature, and flow rate in seawater, as well as the presence of marine organisms attached to surfaces, all directly affect the corrosion process; corrosion cycles vary significantly between different sea areas.