NUMERICAL MODELLING of WAVE-INDUCED LIQUEFACTION AROUND PIPELINES and OFFSHORE CABLES

Submarine pipelines and offshore cables are critical infrastructures for the offshore energy industry. Marine structures like pipelines and offshore cables buried in loose finegrained seabed soil, such as silt or fine sand, maybe under the threat of wave-induced liquefaction. Such failures (flotation or sinking of structures due to liquefaction) have been reported widely in the literature. Observations show that the presence of pipelines/cables can enhance the wave-induced liquefaction susceptibility. This paper presents early results of a numerical modeling study in which the liquefaction potential around a pipeline/cable buried in seabed soil is investigated. A numerical model being developed in the OpenFOAM CFD toolbox under the NuLIMAS (Numerical Modelling of Liquefaction Around Marine Structures) Project is utilized. The results show that the model is capable of simulating the pore pressure buildup around pipelines (or cables), both in near or far field. Additionally, it is shown that different wall boundary conditions of pipelines/cables (i.e. smooth or rough) can be modeled in the numerical model, which is a convenient feature of the model for utilization in practical applications.