Experimental Study Effect of piggyback line on Self-Burial Submarine Pipeline under Steady Current

The pipelines are often laid directly on the erosive bed is capable of self-burial process (Because of local scour around the pipe). Todays, for the transmission of electric and telecommunication cables through the seabed and riverbed, a pipeline with a small diameter is used on top of the main pipe (known as Piggyback line), which can affect the flow pattern around the pipeline. In this study, the effect of attached Triangular and Circular Piggyback lines over the main pipe on the Self-burial depth and the final bed profile were studied. The results showed that the maximum Self-burial depth of the pipe is less than diameter of the pipe. Moreover, the attached Piggyback Line over the main pipe, on average, increased the self-burial depths up to 42%. Also, the value of the Self-burial depth for Triangular Piggyback line was more than Circular Piggyback line. With increase of the Froud number, the maximum Self-burial depth increased.

Keywords:

Self-burial , Pipeline , piggyback line , Offshore , River