ABSTRACT
Pipelines are the arteries of offshore hydrocarbon developments. They transport the hydrocarbon product and other fluids between wells and in-field processing facilities and also to shore. 'Rigid' pipelines are made from steel tubes, with layers of internal and external coating for corrosion, abrasion and impact protection, thermal insulation, and to add weight for improved stability. The analysis of a pipeline involves significant soil–structure interaction. Geotechnical analyses feed into pipeline design, through assessements of: the likely embedment of the pipe after lying; any changes in embedment that may occur during the life of the pipeline; and the resisting forces between the pipe and the seabed that can be mobilised in the axial and lateral directions. Pipeline geotechnics is concerned with the behaviour of the shallowest metre or so of the seabed, so the relevant stress levels are significantly lower than for conventional geotechnical analyses.
