Remaining-Life Prediction and Reliability Assessment of Buried Gas Pipelines under Corrosion and Alternating Loads

Abstract

First, a methodology was proposed for predicting the remaining life of buried gas pipelines subject to corrosion and cyclic loads. Variation in corrosion-defect depth was considered an exponential function of pipeline elapsed time, and the cumulative damage rate was employed to compute pipeline cyclic damage. Because of the presence of nonlinearity in the formulas, an iterative method was used for calculating remaining life and total damage of pipelines with field data. Next, a limit-state function based on remaining-life mode was adopted for estimating pipeline failure probability, and the associated random variables were represented by normal probabilistic distributions. Then the acceptable failure probability and risk interval were combined for assessing pipeline reliability, which was validated with field data.