This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project conducted by the Pacific Earthquake Engineering Research Center (PEER) with the Lawrence Berkeley National Laboratory (LBNL) and funded by the California Energy Commission (CEC). The overall project is titled “Performance-based Earthquake Engineering Assessment Tool for Natural Gas Storage and Pipeline Systems” henceforth referred
to as the “OpenSRA Project.”
The overall goal of the OpenSRA project is to create an open-source, research-based seismic risk assessment tool for natural gas infrastructure that can be used by utility stakeholders to better understand state-wide risks, prioritize mitigation, plan new gas infrastructure, and help focus postearthquake
repair work.
The project team includes researchers from LBNL, UC Berkeley, UC San Diego, University of Nevada Reno, the NHERI SimCenter at UC Berkeley, and Slate Geotechnical Consultants and its subcontractors Lettis Consultants International (LCI) and Thomas O’Rourke. Focused research to advance the seismic risk assessment tool was conducted by Task Groups, each addressing a particular area of study and expertise, and collaborating with the other Task Groups.
This report is the product of Task Group D: Performance of gas storage and pipeline system surface infrastructure. The scope of this report is the experimental program carried out at the University of Nevada, Reno (UNR) to assess the dynamic response of surface natural gas subsystems. It describes the design approach and the experimental setup, presents the test results, derives conclusions, and makes recommendations for future research.
The experiment comprised a piping subsystem which included a vertical storage tank, several pipe connection types, and two pipe sizes. The subsystem was subjected to two different types of ground motions utilizing two of UNR’s biaxial shake tables in tandem. The subsystem remained elastic when subjected to the first set of high amplitude coherent earthquake motions applied uniformly across the subsystem. The second type of motions consisted of variable support motions with large relative displacement across the subsystem. For this second type of motion, progressive inelastic behavior occurred in the piping components. However, despite the large rotations and the significant deformation experienced by the subsystem, system leakage, which was the main metric
for damage, did not occur. This experiment confirmed the resiliency of natural gas pipeline infrastructure subjected to extreme earthquake-induced motions.
The shake table experiment provided a new and unique dataset of high-quality data which will be an important asset for future validation and calibration of numerical models of piping systems in support of numerically-based fragility function generation. Given the myriad of configurations of aboveground piping systems, establishing high confidence in the ability to reliably model system response will be important in future risk assessments.
Two-page summary: click here
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Full List of PEER Reports: click here.
