This paper presents a new algorithmic formulation of the clay and sand pipe–soil interaction models recommended by the DNV-RP-F109 code for dynamic on-bottom stability analysis of submarine pipelines. The pipe–soil force update algorithm is formulated within the framework of computational elasto-plasticity and applies Backward-Euler integration to ensure stability and robustness for large time step sizes. Algorithmic optimization techniques are developed by utilizing a closed-form solution and subincrementation. A numerical verification study covering full cyclic displacement ranges of a 12 inch pipeline is presented. The new formulation is shown to increase the time step size by a factor of up to 50 compared to commercial software tools for on-bottom stability analysis. This achievement will be particularly beneficial for long-duration 3D nonlinear time domain on-bottom stability analysis.

本文提出了一种新的算法公式，该公式由DNV-RP-F109代码推荐用于海底管道的动态井下稳定性分析的泥沙管道-土壤相互作用模型。管道-土壤力更新算法是在计算弹塑性的框架内制定的，并应用Backward-Euler集成来确保大时间步长的稳定性和鲁棒性。通过利用封闭形式的解决方案和子增量来开发算法优化技术。提出了涵盖12英寸管道完整循环位移范围的数值验证研究。与用于底部稳定性分析的商用软件工具相比，新配方显示出将时间步长增加了多达50倍。