PROBABILISTIC ASSESSMENT OF PIPELINE - FAULT CROSSING

Buried steel pipelines transporting oil and oil products play a vital role in the energy supply chain.Pipelines extend to long distances and thus intercepting tectonic faults, when a seismic area is crossed, is often inevitable and may heavily threat the pipeline integrity.Earthquakes and the associated fault displacements are naturally random events and therefore the imposed large ground displacements on the pipeline have to be considered through a probabilistic perspective.In the present study, a comprehensive seismic risk analysis of buried pipelinefault crossing is presented, consisting of two steps.The first step is the probabilistic assessment of the fault displacement accounting also for the pertinent uncertainties.The second step is the pipeline structural analysis.The transition from the seismological data to the structural analysis is realized through the fault displacement components as the selected vector intensity measure.The outcome of the proposed methodology is the strain hazard curves for both tensile and compressive longitudinal strains.The resulting strain capacities are compared to strain demands from structural codes in order to assess the potential of pipeline failure due to local buckling or tensile fracture.Furthermore, uncertainty and disaggregation results from the fault displacement hazard analysis are presented for the selection of the appropriate deterministic design scenario and the evaluation of the fault displacement hazard parameters.Lastly, the proposed process is a reliable estimation tool for seismic risk assessment of pipelinefault crossing and a decision making tool for route selection and application of preventive measures against the consequences of faulting on pipelines.