Resistance mechanism of partially embedded pipelines considering the influence of temperature fields

Abstract

Subsea pipelines are prone to global buckling under high temperature and high pressure. The key to predict buckling is to accurately evaluate the pipe-soil resistance, which is affected by the soil temperature. The effect of temperature on axial resistance has been investigated, but the impact on the transverse resistance has not been well considered. In this paper, incorporating the heat transfer analysis of partially embedded pipelines, finite element models are established to reveal how temperature affects the resistance. The yield envelope of pipe-soil resistance under different temperatures is presented. The results show that the resistance is positively correlated with temperature. Specifically, it is found that the pipeline (w/D=0.5) with high temperature (80 °C) exhibits 23.49% larger maximum pipe-soil resistance than the low temperature pipeline (4 °C). Meanwhile, the temperature affects the plastic strain distribution in the soil, which changes the soil failure mode. In addition, the yield envelope and dividing point between light and heavy pipelines increase significantly with the rise in temperature. Finally, the constructed yield envelopes are adopted in the pipeline buckling model. It shows that lateral pipeline buckling is obviously suppressed by the temperature rise. The research provides a guidance for controlling the buckling of pipelines.