Performance assessment of corroded buried pipelines under strike-slip faulting using stochastic wall loss modeling

Abstract

Buried pipelines are crucial components of civil infrastructure and are essential for transporting content that is essential to human life. Among the numerous threats to buried pipelines, seismic activity poses a significant risk, particularly when pipelines are subjected to permanent ground deformation (PGD), such as faulting. A typical analysis of these pipes under PGD includes assuming an intact pipe without any defects or corrosion. In the current work, a corroded steel pipe crossing a strike-slip fault at right angle is analyzed using three-dimensional nonlinear finite element analysis, and the reduction in capacity for different failure modes is assessed. Different parameters such as corrosion level, diameter-to-thickness ratio, different soil types and steel pipe materials and internal pressure are considered in this study. A probabilistic approach is employed to simulate the inherent variability and uncertainty associated with corrosion along the entire length of the pipe. Furthermore, performance curves are plotted for various failure modes to understand the behavior of pipelines with different levels of corrosion under strike-slip faulting at right angle. The study reveals that corrosion significantly reduces fault displacement across all failure modes, with reductions exceeding 50 % at high corrosion levels. Among the failure modes, cross-sectional flattening tends to allow the highest displacement before failure, while local buckling consistently provides the most conservative limits, particularly in thinner-walled pipes. Additionally, comparisons between uniform and probabilistic corrosion models reveal that relying on uniform assumptions can substantially overestimate pipeline capacity, by as much as 48 %, highlighting the importance of accounting for spatial variability in corrosion patterns.