Many subsea pipelines have been failed during their service period caused by scouring of pipeline support structure. When a submarine pipeline or submarine structure is laid on a sediment bed, and is subject to a current, the pressure difference between the upstream and the downstream of the pipeline or the structure may induce a scour underneath the pipe and submarine structure. According to this problem, the subsea pipeline support structure scouring assessment is studied to forecast the scouring occurrence. Firstly, the sediment incipient velocity is calculated based on scouring theoretical analysis, and then a two-dimensional geometry model is built in FLUENT software, and the actual seabed current velocity is obtained based on numerical simulation by FLUENT software. Through the comparison between these two velocities, the scouring occurrence could be assessed. This method is validated in Indonesia subsea pipeline project.
Bai Y, Ng C, Shen H, et al.Rheological properties and incipient motion of cohesive sediment in the Haihe Estuary of China[J]. China Ocean Engineering, 2002, 16(4) :483-498