Sponsored by California Energy Commission (CEC), this project is to develop a risk assessment methodology that quantifies the earthquake ground motion, fault displacement hazard, landslide and liquefaction risks for California gas infrastructure. Current understanding of seismic threats to gas pipelines and underground gas storage systems rely upon models that are too simplistic using limited empirical data resulting in significant uncertainties in predictions. To improve this, we will conduct high-fidelity soil-structure interaction (SSI) analyses using geohazard characteristics (e.g., displacement magnitude, direction of displacement) and pipeline characteristics (e.g., pipe diameter, thickness), to create models that can predict the resistance (or fragility) of gas transmission pipelines and underground storage fields to the full range of seismic hazards, including ground motion, fault displacement, landslide and liquefaction. The proposed research will develop significantly more accurate probabilistic predictive models for seismic hazards to which distributed gas infrastructure in California is susceptible.