Dynamic Response Interaction of Vibrating Offshore Pipeline and Moving Seabed With Varying Geological and Geo-Mechanical Properties

Abstract

The dynamic response interaction of a vibrating offshore pipeline on a moving seabed is herein investigated where the pipeline is idealized as a beam vibrating on an elastic foundation. In particular the time history effects on physics of the stress distributions on the dynamic interaction predicted on sea state and waves is studied. The spectral density analysis of responses and stress distributions over time is used to predict the anticipated time for pipe burst using the seabed state. The studies also revealed that in general, the seabed acts either as a damper or as a spring and in particular when we have sedimentation, the seabed geology permits the geo-mechanical property of the sediment cover to act only as a damper. As expected, external excitation will increase the response of these pipes for which an amplification factor has been derived. For soft beds, high transverse vibrations were dampened by increasing the internal fluid velocity whereas they became amplified for hard beds.

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