Abstract: Deep-sea pipelines are typically laid on the seabed. Under the influence of their own weight and pipeline-laying operations, they become embedded into the seabed. The embedment depth wini significantly affects the lateral soil resistance exerted by the seabed on the pipeline. Existing research has primarily focused on pipelines with embedment ranging from 0.1 to 0.5 times the pipe diameter D. However, recent studies show that some pipelines embed deeper than 0.5D. We employed the radial point interpolation method-remeshing and interpolation technique with small strain (RPIM-RITSS) to perform large-deformation analyses of the lateral pipe-soil interaction for initial embedment from 0.1D to 1.0D. The method’s effectiveness was validated by comparisons with centrifuge tests and other numerical results. Subsequent analyses examined how initial embedment and pipe weight influence the lateral-buckling mode and soil resistance. A residual-resistance model for lateral buckling, applicable to initial embedment from 0.6D to 1.0D, was proposed to support the safe design of deep-sea pipelines.

Key words: deep-sea pipelines, soft clay, lateral buckling, large deformation, pipe-soil interaction