Performance-Based Earthquake Engineering Assessment Tool for Gas Storage and Pipeline Systems

Earthquakes impact the safety and reliability of gas storage and transmission systems. Current risk studies performed by utility owners and operators are derived from risk scoring that is highly subjective and qualitative, which do not provide the framework for proper incorporation of uncertainties. The reliability of the risk assessments needs improvement through reducing uncertainties with quantitative data. A new open-source seismic risk assessment tool, OpenSRA, was developed to enable system regulators and operators to address challenges posed by the risk from earthquakes and to reliably prioritize the most impactful seismic retrofits for gas infrastructure in California. OpenSRA incorporates new methods to assess the seismic risk of gas infrastructure due to multiple geohazards, and it incorporates new seismic capacity (“fragility”) curves for gas system components based on highly efficient modeling and laboratory testing supplemented by validation processes for more reliable assessments. OpenSRA provides an analysis framework grounded on a methodical performance-based quantitative approach instead of an ad hoc qualitative approach. With OpenSRA, assessments are built from robust quantitative data for seismic demand and seismic capacities of gas storage, pipeline systems, and their components.