Laboratory Testing of Full-Scale Pipes Partially Embedded in Soil to Study Soil-Pipe Interaction of Offshore Seabed Oil and Gas Pipelines: Initial Observations

The geotechnical aspect of the design of off-shore oil and gas pipelines is a challenge due to inherent uncertainties in predicting soil-pipe interaction behaviour. Physical modeling is often sought after to gain insight into such problems. This is especially true for pipelines laid in deep waters that are partially embedded in the seabed. This paper presents initial observations arising from full-scale laboratory simulations of typical soil-pipe interaction scenarios of partially buried steel pipes. Bare and epoxy-coated NPS18 steel pipes, each measuring 2.5 m in length, were separately tested in a soil chamber by simulating: (i) lateral pipe displacement; and (ii) longitudinal pipe displacement, under partial embedment in two idealized soil bed models, i.e., in a coarse-grained soil bed model with full drainage, and a fully-saturated fine-grained soil bed model with partial drainage.