Numerical modeling of soil–pipe interaction of single pipeline at shallow embedment in clay by hypoplastic macroelement

Abstract

Nowadays, the numerical analysis of submarine pipelines of offshore oil and gas industry is a big challenge in engineering design. A simple, fast and accurate numerical tool is proposed in this article based on the macroelement concept. The novel macroelement is within the framework of hypoplasticity and can consider static monotonic combined (multi-directional) loads for shallow embedded pipelines in clay. The incremental nonlinear constitutive formulas are defined in terms of generalized forces and displacements and an enhanced function of failure surface is introduced. A series of empirical formulas are proposed to describe the stiffness variation trends for soil–pipeline interaction. Model predictions show that the proposed macroelement is proved to be an efficient alternative approach compared to the traditional finite element analysis. The computational cost is thus much reduced for the pipeline design.