Comprehensive numerical analyses of the seismic performance of natural gas pipelines crossing earthquake faults

Coseismic fault displacement has been recognized as a critical hazard to natural gas transmission pipelines crossing earthquake faults. Prior studies on pipeline response to fault displacement were limited to specific types of pipes and faults, which were indeed constrained by the computational resources. As part of an effort to develop a Bayesian model to relate ground displacement in pipeline strain, we analyze more than 217,000 finite element models of gas pipeline fault crossings, which consider the pipe-soil interactions with both pipe and soil material nonlinearities. Such an enormous number of simulations are selected based on comprehensive sensitivity analyses and cover the most important parameters of gas pipelines in terms of combinations of the following: (1) pipe dimensions and materials, (2) soil properties, and (3) style of faulting and characteristics of fault movements. We devise an automated workflow for input generation-simulation submission-output extraction, by utilizing more than 10,000 cores high-performance super-computing facilities. Finally, we examine the pipeline response for every combination, by investigating the evolution of maximum compressive and tensile strains in the axial direction along the pipe over the fault displacement. These numerical analyses resulted in a comprehensive database of pipeline fragilities crossing earthquake fault for seismic risk analysis of natural gas infrastructure in an earthquake region.