Time-dependent lateral bearing behaviour of corrosion-damaged RC pipe piles in marine environments

Chloride-induced steel corrosion is one of the major causes of the premature deterioration of reinforced concrete (RC) pipe piles in marine environments, inducing the degradation of the long-term resistance of RC pipe piles subjected to lateral loading. It is essential to conduct systematic research on the deterioration law of the lateral bearing behaviour of RC pipe piles in marine environments. In the present study, a mathematic model is developed to describe the chloride diffusion into an RC pipe pile. A time-dependent reinforcement corrosion model is adopted to simulate the reinforcement corrosion process in an RC pipe pile. In addition, the relationship between the degradation coefficient of the pile stiffness and the corrosion loss is established based on the experimental investigation. Based on the fitting relationship, the attenuation law of the pile stiffness of corrosion-damaged RC pipe piles in marine environments is investigated. The time-dependent lateral bearing behaviour of corrosion-damaged RC pipe piles in marine environments is investigated using the finite difference method. The analysis results demonstrate that the lateral bearing behaviour of RC pipe piles in marine environments has obvious time-varying characteristics. The pile stiffness decreases nonlinearly with the increase in exposure time. The degradation coefficient of the pile stiffness reduces to 0.32 and 0.30 for Ca = Cb = 4.5 kg/m3 and Ca = Cb = 9.0 kg/m3, respectively, for an exposure time of 90 years. The maximum negative shear force and lateral deflection increase with the increase in exposure time, whereas the bending moment decreases with the increase in exposure time.