On lateral and upheaval buckling of subsea pipelines

• A new interpretation of localisation in lateral buckling based on isolated half-wavelength model.
• Tabulated analytical solution for upheaval buckling under different local imperfections.
• Comparison between lateral and upheaval buckling in a long pipeline.
• Some of the current results are different from previously published results.

The lateral and upheaval buckling of subsea pipelines is investigated in this paper. For lateral buckling, analytical and numerical studies are conducted and compared and a new interpretation of localisation is given based on an isolated half-wavelength model. For upheaval buckling, a tabulated analytical solution based on a long heavy elastic beam resting on a rigid frictional foundation is given and the response under three types of localised initial imperfection is compared. A comparison of the lateral and upheaval responses of a subsea pipeline is made and indicates that excessive bending stress can be induced, particularly under upheaval buckling. The paper also highlights some differences between the current and previously published results.