Abstract: To investigate the local crushing and winkling behaviors of buried pipelines under reverse faults, this study has analyzed the buried pipelines in the loess layers and established a numerical calculation model for pipe-soil coupling. Furthermore, it has examined the process of deformation and local buckling in buried pipelines under reverse faults and evaluated the influence of internal pressure, diameter-to-thickness ratio, and the number of dislocations in the local buckling of the pipelines. Research results show that with an increase in the number of dislocations, stress concentration can be observed on the pipelines on both sides of the fault layer gradually leading to local buckling. The deformation curve of the buried pipeline changes from the S-shape to Z-shape. Moreover, the deformation of the pipeline on both sides of the fault plane is neither symmetrical nor anti-symmetric. The upper panel has experienced more serious pipe buckling than the lower panel. When the number of dislocations is three times higher than the diameter of the pipe, the axial strain of the pipeline increases rapidly. Pipelines with no pressure and low pressure have experienced crushing. As the internal pressure increases, crushing will further develop into wrinkling, and the wrinkle width of the pipe increases with the internal pressure. The distance between the buckling part of the upper panel and the fault plane is less affected by the internal pressure and the diameter-to-thickness ratio, while that between the buckling part of the lower panel and the fault plane reduces with the increase of the internal pressure under crushing and increases with the increase of internal pressure under wrinkling. The maximum axial strain of the pipeline demonstrates different patterns according to the variations in the diameter-to-thickness ratio and the number of dislocations.

Key words: buried pipeline, reverse fault, crushing, wrinkling, numerical simulation, local buckling