Mechanical Behavior Analysis of the Buried Steel Pipeline Crossing Landslide Area

Landslide movement is one of the threats for the structural integrity of buried pipelines that are the main ways to transport oil and gas. In order to offer a theoretical basis for the design, safety evaluation, and maintenance of pipelines, mechanical behavior of the buried steel pipeline crossing landslide area was investigated by finite-element method, considering pipeline-soil interaction. Effects of landslide soil parameters, pipeline parameters, and landslide scale on the mechanical behavior of the buried pipeline were discussed. The results show that there are three high stress areas on the buried pipeline sections where the bending deformation are bigger. High stress area of the compression side is bigger than it on the tensile side, and the tensile strain is bigger than the compression strain in the deformation process. Buried pipeline in the landslide bed with hard soil is prone to fracture. Bigger deformations appear on the pipeline sections that the inside and outside lengths of the interface are 30 m and 10 m, respectively. The maximum displacement of the pipeline is smaller than the landslide displacement for the surrounding soil deformation. Bending deformations and tensile strain of the pipeline increase with the increase in landslide displacement. Bending deformation and the maximum tensile strain of the pipeline increase with increasing of the soil's elasticity modulus, cohesion, and pipeline's diameter–thickness ratio. Soil's Poisson's ratio has a great effect on the displacement of the middle part, but it has a little effect on other sections' displacement.