Failure assessment on the suspension-settlement deformation of oil and gas pipelines

Pipelines are often subject to external loads caused by the settlement deformation in the actual running process, while existing pipeline failure evaluation criteria and methods are mostly limited to the impacts of internal pressure on the pipe. In view of oil and gas pipeline suspensionsettlement deformation, mechanical models, finite element analysis, excavation tests and other methods are used for systematic research and stress distribution of defect-free and defect-bearing suspended pipeline, which is simulated to draw a conclusion that the equivalent stress reaches the maximum value when defects occur on the bottom of the pipeline. Stress change of maximum stress point and other test data are obtained through the excavation test, the feasibility of finite element used in engineering practice is verified and it is pointed out that actual engineering assessments need to consider the impact of the defect location, soil and other factors.