Abstract: Vertical load, as a common yet easily overlooked hazard factor, can cause the failure of buried PE pipeline. Based on the independently developed pipeline-soil interaction test platform, this paper carried out a model test of the interaction between the foundation soil and buried PE pipe with joint, and and explored the mechanical response of buried PE pipeline with joints under vertical loads and the mechanism of pipe-soil coupling processes. The results showed that the failure of buried PE pipeline systems under vertical loads was prone to start at the joint. Firstly, micro-cracks emerged from the weld seam of the joint. Then, under the continuous action of vertical load, the cracks expanded along the weld seam. Additionally, under the action of vertical load, the horizontal displacement of the pipeline intensified the deformation of the pipeline. Buried PE pipelines, under the action of vertical load, underwent overall tensile deformation along the axis. The longitudinal strain of the pipeline was mainly manifested as tensile strain at the top of the pipeline, and the compressive strain at the bottom of the pipeline. Due to the dissipation effect of soil on vertical load, increasing the burial depth of pipelines can effectively reduce the destructive effect of vertical loads on pipelines.

Key words: pipeline with joint, vertical load, pipe deformation, failure, model test