Dynamic response of buried pipeline under the sliding instability of slopes in cold regions

Abstract

In order to study the dynamic response behavior of buried pipelines under the instability and sliding of slopes in cold regions, the buried pipelines in cold regions are taken as the research object. Considering the characteristics of large deformation and collapse of unstable soil, the material nonlinear characteristics of pipeline and foundation soil, and the contact nonlinear characteristics among pipeline, unstable slope and foundation soil, the nonlinear dynamic model of buried pipeline under slope instability is established by SPH-FEM (smoothed particle hydrodynamics-finite element method) method. Compared with the literature results, the maximum error is 0.67%, which verifies the rationality of the model and algorithm. Then, pipeline’s dynamic response with different influencing factors are studied. The results show that: The residual stress of pipeline decreases with the increase of pipeline position, with the decrease of diameter-to-thickness ratio of pipeline, and increases first and then decreases with the increase of freezing depth of foundation soil, with the variation amplitude of residual stress of 12.72%, 23.1% and 14.56% respectively. The pipeline displacement varies with different influencing factors, the maximum variation in the freezing depth of foundation soil can reach 22.6 mm, while in the diameter-to-thickness ratio and pipeline position can reach 6.9 mm and 5.4 mm respectively. The degree of local dent of the pipeline is most pronounced at the peak time,when the freezing depth of the foundation soil is 0 m, the local dent depth can reach 4.92% of the pipeline’s outer diameter. Relevant research methods are expected to provide guidance for the integrity management of slope pipeline engineering in cold regions.