Performance Evaluation of Natural Gas Transmission Pipelines in Landslides

The study aimed to evaluate the behavior of typical natural gas transmission pipelines in landslides and investigate the effect of various parameters such as internal pressure, pipe diameter, and soil type on their active lengths. Nonlinear Finite Element Analyses (FEA) were performed using the Winkler-type beam-on-spring model to evaluate the pipeline response in landslides. The FEA results showed that the stress and strain distribution along the pipeline were primarily positive, which indicated that the ground movement was resisted by axial tension force (membrane action) of the pipeline. The maximum axial strain occurred at the beginning and the end of the landslide zone, indicating that the pipeline would fail at these locations. The FEA results also indicated that the maximum axial forces in all cases were very close to the section capacity of the pipe, indicating that landslide-induced ground displacements resulted in very high axial force and relatively low bending moment in typical natural gas transmission pipelines.The PRCI guidelines provide an equation for estimating the anchor length of buried steel pipelines, but the results of this study indicate that the anchor lengths are much larger than those calculated by the PRCI equation. A proposed equation based on ultimate strength of the pipe section is suggested for calculating anchor length, which gives a good estimate of the anchor length with an average error of ۴% relative to the analytical results. Overall, the study concluded that the internal pressure of the pipeline had no significant effect on the anchor lengths of the pipelines, and the proposed equation provides a more accurate estimate of the anchor length of typical natural gas transmission pipelines.

Keywords:

landslide , Gas Transmission Pipeline , Anchor length , finite element analysis , Failure