Scour depth beneath a pipeline undergoing forced vibration

Abstract

This paper studies the coupling effect of the pipeline vibration on the seabed scour. A vertical two-dimensional model is applied to numerically investigate the local scour below a vibrating pipeline with different amplitudes and periods. Using the scour underneath a fixed pipeline as a reference, this paper focuses on the impact of the pipeline vibration on the equilibrium scour depth. Generic relationships are established between the non-dimensional scour depth and the non-dimensional vibrating parameters, i.e., amplitude and frequency. The normalization process takes into account the influences of such parameters as the incoming flow velocity, pipe diameter, and Shields parameter. An empirical formula is proposed to quantify these relationships.

Keywords

• Offshore pipelines
• Scour
• Numerical models
• Vibration
• Sediment transport