Surface roughness characteristics of corroded steel pipe piles exposed to marine environment

Abstract In determining the residual capacity of corroded steel structures, many studies have focussed solely on the section’s remaining thickness and its strength. However, it is anticipated that the condition of the corroded surface may also have an influence on the performance of these structures. This paper presents results of the evaluation of surface characteristics of corroded steel piles exposed to marine conditions at varying exposure water levels for 19.5 years. A comprehensive study on the roughness characteristics of these corroded steel pipe piles was done by calculating a number of general geometrical properties, as well as descriptive statistical parameters. By subdividing the pipe surface into smaller sampling areas of 100 mm × 100 mm, and employing a Gaussian filter to obtain roughness surface, the variation of topographical features on the corroded surface were studied. Variations between the degree of corrosion, in terms of thickness reduction, and surface roughness characteristics are reported. The study revealed that unlike the amplitude characteristic feature of the surface roughness, which increases with increasing level of corrosion, wavelength remains unaffected by the level of corrosion.