RELIABILITY OF BURIED PIPELINES WITH CORROSION DEFECTS UNDER VARYING BOUNDARY CONDITIONS

초록

This paper presents the effects of boundary conditions of failure pressure models for buried pipelines on failure prediction by using a failure probability model and a finite element analysis. The first order Taylor series expansion of the limit state function (LSF) is used in order to estimate the probability of failure associated with corroded defects under varying boundary conditions for long exposure periods in years. Two failure pressure models based on a failure function composed of failure and operation pressures are adopted for the assessment of pipeline failure. The effects of random variables such as varying boundary conditions on the failure probability of the buried pipelines are systematically analyzed by using a failure probability model for the corroded pipeline. Furthermore, the engineering results estimated by a failure probability model are compared with those obtained by a finite element analysis. The influences of statistical distributions, such as normal and lognormal, of random variables on the failure probabilities are also investigated in detail.