Safeguarding the integrity of large-diameter steel pipelines subjected to differential ground settlements

Abstract

The paper describes the application of a novel and promising concept, aimed at absorbing ground-induced displacements due to soil subsidence in buried steel pipelines entering or exiting concrete or rigid structures. In particular, the use of a patent pending concept of small projections is proposed, appropriately located along the pipeline, at the critical zone of soil subsidence, where deformation of the pipeline is expected. Using this solution, the pipeline is able to deform in a controlled manner such that there is no loss of pressure containment and the pipeline will continue to perform long term. Advanced finite element simulations have been employed to model the projection and characterize its structural behavior. The present concept is applied on an 84-in. diameter buried steel pipeline, and the results indicated that the use of projections at appropriate locations improves structural performance, decreasing both strain in the pipeline wall and the reaction forces and moments at the concrete wall. © 2021 ASCE.