Wave-Induced Response of Submarine Pipeline Embedded in Porous Seabed

Abstract

Submarine pipeline have been used extensively to transport natural oil and gas. The design of pipeline is a challenge for coastal engineers. In the past decades, many researches had focused particularly on solving wave-induced pipeline instability problem. However, this problem has not been fully understood because of the complicated soil behavior. It has been well known that when water waves propagate over a porous seabed, the dynamic pressure on the sea floor fluctuates with the passing waves. Such fluctuations induce variations of the pore pressure and effective stress within the marine sediments, and cause the deformation or even failure of the seabed skeleton. Wave-induced pore pressure and resultant liquefaction in a porous seabed has been recognized as a key factor for pipeline failure.To explore the mechanism of the pipeline instability, the partly dynamic (u-p) for the wave-induced response of the seabed is adopted. In partly dynamic analysis, the u-p formulation in which both displacement and pore pressure are the field variables, is adopted considering the acceleration of soil skeleton. A parametric study is carried out and the resulting response from the partly dynamic are presented for various representative seabed and wave parameters.