4. Assessing Seismic Response of Utah Gas Systems

The potential damage to lifelines from even moderate earthquakes can have significant and widespread effects on community well‐being. Recently, under the sponsorship of the United States Geological Survey, researchers from California cooperated with a utility in Utah to analyze the seismic safety of natural gas facilities in Utah. They identified pipelines by system importance, size, and material, and then assessed the probability of structural damage to these components. These estimates, which reflect knowledge of Wasatch Front fault mechanisms, and an ability to model numerous seismic events by computer, are yielding significant knowledge of possible piping responses. Project results included the number and location of possible pipeline breaks for various seismic events. This information was used to estimate gas loss and resultant system pressures. This, in turn, is currently being used to guide future system reinforcements, replacements, and installation of emergency system isolation valves. This project, involving the close interaction of both the utility and the research firm, is a good example of the type of practical research needed by industry.