Nonlinear structural responses of the buried oval steel pipelines crossing strike-slip faults

The permanent ground deformation may lead to bending failure or fractures of the buried steel pipelines. In practical applications, the buried pipelines may also exhibit ovality defects due to soil pressure, gravity of the pipeline, and misalignment of joints, which have the potential to diminish the load-bearing capacity of the buried pipelines. This paper introduces a comprehensive analytical methodology to examine the dynamic behavior of pipelines with different initial ovality defects subjected to strike-slip faults. A modified permissible lateral displacement function is introduced to determine the strain distribution of the deformed pipelines. One may predict the yield displacement of the oval pipelines accurately based on the yield theory of classical beams and the static equilibrium method. Then, the accuracy of the proposed method was validated by developing a finite element model and other results. Good agreement was reached characterized by the yield displacement and the yield strain, respectively. Finally, a parametric analysis was conducted on the effects of different ovality, steel grades, diameter-to-thickness ratios, fault inclination angles, and soil properties on the displacement and strain distributions of the deformed pipeline.