Study on response patterns and influencing factors of buried pipelines with corrosion defects under fault action

Abstract

It is evident how corrosion flaws affect the tension and strain of pipelines that pass oblique-slip faults. The pipeline is very risky and is more likely to experience tensile and buckling damage when corrosion develops in the major deformation region of the pipeline. This will also significantly diminish the pipeline's failure slippage. This research uses a three-dimensional finite element modeling of trans-fault pipes to study the mechanical reaction and influencing factors of corroded pipelines under the action of oblique-slip faults. It is determined that the distribution of stress and strain as well as the pipeline's extension trend are changed when corrosion faults are present. The concentration of tensile and compressive strain along the corroded circular cross-section at the time of damage, followed by a gradual expansion through the entire corroded circumferential cross-section, and the pipeline's extrusion, folding, and bulging, are the manifestations of the influence of corrosion defects on the pipeline at damage. Tensile and compressive strains in the pipeline increase, failure slippage is reduced, and the pipeline experiences tensile damage and corrosion. The length of the pipeline corroded in the circumferential direction, the length of the corroded length in the direction of corrosion along the pipeline axis, and the corrosion depth increase all contribute to these outcomes. The location of corrosion defects has the greatest influence on the dynamics of the pipeline and is most dangerous in the large deformation section from -10 m to 10 m; the corrosion effect is very small when the corrosion is located on the right side of the fracture surface at 25 m. The risk of buckling damage is higher in this scenario, where the corrosion depth has the greatest effect. The conclusions of this paper can be used as a reference for the seismic and corrosion-resistant design of cross-fault pipelines.