Numerical modeling of seabed ice scour

Abstract

Abstract In coastal regions throughout arctic oceans the seabed is frequently scoured or gouged by moving bodies of ice such as icebergs and sea ice keels associated with pressure ridges. Ice scouring may present a severe environmental hazard pertaining to marine pipelines and other seabed installations. Lateral loading due to excessive movement of sub-soil may lead to failure of the buried pipelines. To facilitate a rational design of marine pipelines, a model is therefore required to evaluate the subscour soil deformation. This paper describes a numerical approach for analysing the seabed response during ice scour. A finite element model, based on large displacement and plastic formulation, was adopted. Results from 2-D finite element analyses compared reasonably well with experimental data obtained from geotechnical centrifuge tests. The subscour soil movements with a buried pipeline were investigated by 3-D finite element analyses. The results show that in certain cases, a pipeline may not have significant influence on the subscour soil deformation.