Reliability evaluation of locally corroded X80 pipeline subjected to accidental earthquake considering geotechnical discontinuities

Abstract Local corrosion can affect the mechanical properties of X80 steel pipelines and redistribute local stress concentration under dynamic loading. Investigation of the failure pressure of buried pipelines containing multiple corrosion defects subjected to earthquakes is vital for pipeline safety. In-line inspection (ILI) data is introduced to estimate and update the 3D random corrosion growth model, embedded in the development of nonlinear finite element analysis (FEA). The novelty of this work lies in the development of a nonlinear FE dynamic model about typical spatiotemporal evolution of corrosion pipelines with multi-failure mode, which implements performance-based reliability assessment considering vertical heterogeneous soil structure. The system reliability is estimated by combining improved equivalent component approach (IECA) and extreme value theory (EVT). Examples are illustrated to prove that the proposed model is feasible for corroded pipelines under an earthquake to execute a multi-failure mode reliability assessment to find the possible failure pressure.