Performance-Based Seismic Assessment for Pipelines and Related Midstream Facilities

Abstract The safety and reliability of pipelines and piping components for any infrastructure network are crucial, particularly in regions prone to seismic activity. Since midstream facilities play a key role in the energy supply and water conveyance chains, safeguarding these assets from earthquakes is paramount as the consequence of failure can be devastating, leading to, for example, possible immediate loss of life at facilities or complete loss of water supply across municipalities. Particularly for the latter, in a worst-case scenario, the complete loss of water supply would have significant chain-reaction effects in cases where water is required for post-earthquake response and recovery (e.g., firefighting, medical, sanitation, industrial cooling, potable water, etc.) Seismic events pose unique challenges for pipelines and facility piping systems. Unlike buildings or bridges, pipelines are elongated structures that traverse diverse terrains, making their response to ground motion complex and site-specific. Specifically, these systems often span long distances, passing through different geological conditions and interacting with various structures. A performance-based seismic assessment addresses these challenges by moving beyond the traditional “life safety only” approach, which focuses solely on preventing collapse, using traditional seismic assessments that rely on prescriptive codes and standards to consider the functionality of the system after an earthquake. The ever-evolving field of earthquake engineering has paved the way for the use of this more sophisticated approach. Performance-based seismic design is particularly relevant for pipelines and facility piping, where continued operation is critical even in the aftermath of a seismic event. This methodology also addresses the fact that damaged sustained by pipeline assets may not be easily distinguishable and will require screening and triage based on measured ground shaking and observed condition of the asset. Performance-based seismic design methodology offers a comprehensive understanding of the behavior and resiliency of pipelines and facility piping systems under seismic ground shaking, allowing for a more accurate evaluation of their performance, and required post-earthquake mitigations. This work summarizes a performance-based approach with distinct levels of assessment, ranging from visual inspection-level screening to detailed assessments based on site-specific response measurements (e.g., accelerometers, fiber optics), that facilitate quick interpretation and execution of pipeline asset mitigation strategies, as required.