Dynamics of a submarine pipeline by excited by waves

A submarine pipeline on the seabed will adjust its shape to the sea bottom profile. The sea bottom profile is not perfectly flat. One can encounter irregularities in the sea bottom due to slopes, lumps and gullies. These irregularities are already present at the time the pipeline is installed. Because the pipeline has a certain bending stiffness, it will not be able to follow all bottom irregularities and the pipe will lose contact with the sea bed. This results ln a free span, which can respond dynamically to the loads imposed on the pipe. This phenomenon gives rise to three aspects of the dynamical behaviour of the pipelines. First, it is necessary to be able to calculate natural frequencies of pipeline spans. Second, the hydrodynamic forces that are imposed on the pipe must be known. Finally, the dynamic behaviour must be known in order to calculate the displacements caused in case of possible resonance.Hydraulic EngineeringCivil Engineering and Geoscience