Finite Element Analysis of Offshore Pipelines Overlying Active Reverse Fault Rupture

The paper investigates the behavior of buried offshore pipelines overlying active reverse faults using the finite element (FE) tool Abaqus. In the FE analyses, the pipeline is modeled with 3D shell elements and the soil with continuum elements. Equivalent boundary conditions are imposed at both pipeline ends to account for the elastic response in the far-field away from the fault. Nonlinear materials, nonlinear interactions, and nonlinear geometries are adopted.The Mohr-coulomb constitutive model with strain-softening is used to model the soil behavior and true stress-strain properties are incorporated to model the response of the pipeline steel material. The effects of soil properties, pipeline diameter, diameter to thickness ratio, and fault displacement are investigated. The results focused on analyzing the pipeline deformations, the axial strains, and the buckling behavior of the pipeline with increasing vertical bedrock displacement. Critical compressive strains are calculated and compared with the DNV code provisions.