Life-cycle cost assessment of buried steel gas pipelines subjected to transient ground deformation

Gas pipeline failures can lead to substantial economic and environmental loss. Thus, comprehensive seismic-resistant designs and risk mitigation strategies for gas pipelines are essential. Typically, in the seismic design of gas pipelines, only construction costs are considered. In this study, a cost-effective life-cycle framework is developed to design seismic-resistant buried gas pipelines. This framework involves modeling the pipeline using finite element methods, conducting incremental dynamic analyses, extracting seismic fragility curves, and calculating expected annual losses. This framework is applied to a designed gas pipeline network as an illustrative case study to show how the framework works. The case study includes pipelines with varying diameters and thicknesses of 20 and 30 inches. The results reveal how design parameters influence both seismic vulnerability and total life-cycle cost, offering valuable insights for optimizing resilience-oriented pipeline design. Increasing seismic intensity significantly raises expected life-cycle losses, underscoring the trade-off between construction cost and seismic performance.