Interaction Between Vibrating Pipe and Erodible Bed

Abstract

This paper reviews the results of an experimental investigation of the interaction between an erodible bed and a pipeline vibrating in the transverse direction to a current. A spring‐supported rigid cylinder is used as a model pipe. First, the influence of pipe vibration on the scour process is studied. The experiments show that pipe vibration induces extra erosion, resulting in relatively larger scour depths and scour widths than when the pipe is held fixed. The effect is most pronounced for pipes elevated slightly above the static bed, and ceases to exist for gaps of one pipe diameter or larger. Second, the influence of scour on pipe vibration is studied. A scour hole is produced on a loose sand bed. The model pipe is placed above (as well as in) the scour hole. The amplitude and frequency responses of cylinder vibration are obtained. Experiments show that the effect of scour on the pipe response can be significant; the vibrations are found to be dominated by vortex shedding even if the pipe is placed very close to the original undisturbed bed.