Effect of corrosion on soil-structure interfacial shearing property and bearing capacity of steel foundation in submarine soil environment

Abstract

As a common type of foundation in ocean engineering, steel foundation encounters great corrosion risk and serious safety hazards throughout its lifecycle. Besides reducing the thickness of steel members, corrosion also has a significant impact on the soil-structure interfacial shearing property by changing the roughness characteristics of steel surface, and eventually affects the bearing capacity of steel foundation in submarine soil environment. In this study, electrolytic accelerated corrosion experiments are conducted first to prepare corroded steel samples suffered different degrees of corrosion. Then, the effect of corrosion on the soil-steel foundation interfacial shearing property is investigated by interfacial shearing experiment and discrete element numerical simulation. The analysis results show that the interface shearing strength under different corrosion degrees can be regarded as following Mohr-Coulomb strength theory. The shearing strength parameters, i.e. the interfacial cohesion and interfacial friction coefficient, increase with the corrosion degree. Finally, the influences of corrosion on the bearing capacity of a steel pipe pile foundation are studied by finite element simulation, with considering the steel thickness reduction and the variation of soil-steel interfacial shearing strength. The numerical results demonstrate the necessity of considering the variation of the interfacial shearing property induced by corrosion.