Upgrading of quay walls at the Ravenna port, Italy: evaluation of the steel piles degradation after a long working life

In the context of a challenging project aimed at the upgrading of some old quays in the port of Ravenna (Italy) an extensive survey was conducted to determine the level of degradation of the most significative structural elements. The quays were essentially constituted by anchored sheet pile retaining walls in which the main structural elements were steel profiles. Therefore, the main point of concern was the degradation of the steel piles after a long-lasting exposure to the sea water. The corrosion of steel structures in marine environment is a well-recognized problem for maritime engineering, therefore nowadays a relevant part of the designing effort is oriented towards improving the durability and to minimize the cost of maintenance of infrastructures. However, data from real experience are not frequent. This paper presents some results of the inspection carried out on quays in the Ravenna port after an operative life between 21 to 29 years, focusing on the condition of the steel piles. Data include ultrasonic measurements of the thickness and laboratory analyses of steel samples. Although the environmental conditions were not particularly favourable, the results indicate that the degradation of the profiles in the permanently immersed zone was very limited.