System reliability of corroded pipelines considering spatial and stochastic dependency in irregular zones

Abstract

This paper presents a probabilistic methodology for assessing the system reliability of corroded pipelines subjected to spatial and stochastic dependency, taking into account irregular zones (elbows, weld joints, and flanges). The space-variant corrosion and residual stress are considered by the mean of Karhunen-Loève expansion in order to take into account spatial variability of residual stress and soil aggressiveness over the pipe's entire length. The failure probability is evaluated by a series system combination using Monte Carlo simulations. Finally, the proposed model is applied to gas pipeline crossing several soil types in order to show the effects of the main parameters of the system, where the irregular zones have a significant influence on the pipeline system reliability and that the developed model can provide valuable information for decision-makers to improve system reliability performance.