Numerical Modeling of Wave-Induced Liquefaction around Pipelines

Abstract

This paper presents the results of a numerical modeling study of wave-induced liquefaction around offshore structures. The finite-element model was first validated against both analytical solutions and laboratory data and was shown to be able to reproduce the observed behavior of the pore pressure variations. The model includes a constitutive model that can predict both residual and momentary liquefaction. The model was used to study liquefaction around a buried pipeline under wave action. In the analysis, it was assumed that the soil in the trench was loose and therefore susceptible to residual liquefaction. The numerical modeling focused on some of the questions that were raised in the physical modeling studies of Sumer et al. in 2006 and Teh et al. in 2003. In particular the influence of pipe diameter, boundary conditions around the pipeline, trench depth, etc., have been assessed and the results are in general agreement with the experimental findings.