Pitting corrosion significantly compromises the structural integrity of pipelines, reducing their service life and increasing the risk of catastrophic failure. One widely adopted method to address this issue is the utilization of a cured-in-place pipe (CIPP) liner. However, studies are needed to understand how existing pitting corrosion affects the performance of pipelines with CIPP liners. In this study, we computationally investigate the impact of pitting corrosion on the structural performance of underground cast-iron pipelines rehabilitated by CIPP liner. First, a comprehensive three-dimensional finite element model is developed to simulate the behavior of cast-iron pipes with and without CIPP liner rehabilitation. We define varying pit geometries and corrosion patterns in the numerical model. The model simulates the progressive material loss and stress concentration at the pit locations under internal pressure loading conditions. The analysis indicates that factors such as pit depth, distribution, size, and shape have a significant influence on the stress concentration of the pipelines. Subsequently, this study investigates the effectiveness of using CIPP liners as a rehabilitation method for pipes with pitting corrosion. The investigation evaluates how CIPP liners restore the load-bearing capacity of damaged pipes and redistribute stress concentrations induced by pitting corrosion. The results demonstrate that CIPP liners considerably improve structural integrity and extend the service life of the corroded pipelines. This study highlights the need for enhanced corrosion management strategies, emphasizing the importance of predictive maintenance. The computational assessment results also provide an approach for improving current rehabilitation techniques, such as CIPP liners, to extend the service life of aging pipeline infrastructure. Furthermore, the findings suggest the need for optimized CIPP design to ensure both cost efficiency and long-term structural integrity, supporting more sustainable and resilient pipeline rehabilitation strategies.
Duan et al. (Thu,) studied this question.