FEM Model for Pipeline Analysis of Ice Scour: A Critical Review

This paper presents results from two different Finite Element (FE) pipeline ice-scour models employing pipe and shell elements that incorporate large deformations and metal plasticity. The main objective of this paper is to investigate the effects and implications of some of the main pipeline design parameters on the response of the pipeline determined by using Winkler models and soil displacements that are based on an empirical scour function commonly used in recent literature. The current model is two dimensional in terms of deformed pipe geometry and incorporates temperature and pressure stiffness effects. A detailed study of the soil displacements underneath and around the scour and a three-dimensional continuum based ice-soil-pipe interaction model is being presented in a different paper. The paper discusses the limitations and implications of the Winkler modeling and compares results obtained using different Winkler spring models. It illustrates the effects of pipe temperature (and pressure), pipe burial depth, and scour width. A comparison of pipe response using shell and pipe elements is also presented. This paper presents results from the FE models for a typical gathering pipeline. The pipe is taken to be a 16 inch diameter and 0.75 inch wall thickness API 5L X65 Specification line pipe.