Buried steel pipelines crossing strike-slip faults

Abstract

The paper examines the behaviour of buried steel pipelines crossing active strike-slip faults. The vertical fault plane is crossed by the pipeline at an angle ranging between zero and 45 degrees, causing significant plastic deformation in the pipeline. The investigation is numerical, simulating the nonlinear response of the soil-pipeline system rigorously through nonlinear finite elements, accounting for inelastic material behaviour of the pipeline and the pipe and the soil, as well as contact and friction on the soil-pipe interface. Steel pipes with D/t ratio and material grade typical for hydrocarbon pipelines are analyzed, through an incremental application of fault displacement and appropriate pipeline performance criteria, defined within a strain-based design framework, are monitored throughout the analysis. The effects of various soil and linepipe parameters on the structural response of the pipeline are examined. The numerical results from the present investigation determine the fault displacement at which the specified performance criteria are reached, including the effects of internal pressure. Copyright © 2012 by the International Society of Offshore and Polar Engineers (ISOPE).