Performance Assessment of Continuous Buried Pipelines Under Earthquake Loadings

Industrial plants are complex systems that need stringent requirements to ensure structural safety. If large amount of toxic or flammable materials are handled, the consequences of failures can affect wide surrounding areas. The prediction and prevention of possible accidental scenarios triggered by the interaction of natural disaster with industrial equipment depend upon the reliability of available tools for structural design and hazard assessment. In this paper, attention is focused on industrial pipelines and on damages suffered by these structures under seismic sequences. Available data have been classified on the basis of seismological, geotechnical, structural and performance parameters, in order to assess the main factors affecting the seismic vulnerability of pipelines. An observational correlation between pipeline performance and relevant earthquake intensity measures for both transient and permanent deformations is derived. Moreover, compared to the available literature performance parameters based on a repair ratio, new fragility formulations have been built on the basis of the failure probability of pipelines. This circumstance provided some interesting remarks on the loss of containment, which has been largely demonstrated as the main issue for qualitative and quantitative risk assessment depending on relevant failure mechanisms.