Seismic Risk Analysis of Lifelines: Preliminary Results for the Case-Study of L’Aquila ENEL Rete Gas

This paper presents the seismic risk assessment of L’Aquila gas distribution network in a performance-based earthquake engineering framework. The study was structured in three basic activities: (1) seismic hazard characterization both in terms of ground motion and permanent ground deformation; (2) characterization of system’s vulnerability via fragility curves available in literature; (3) performance evaluation in terms of connectivity. In the paper all issues involved in seismic risk analysis of this kind of systems are discussed with respect to a selected part of the whole network. In particular, the importance of modelling spatial correlation of ground motion and geotechnical hazard on risk assessment was investigated. Results indicate that the system performance may be underestimated when spatial correlation and ground failure are ignored. Moreover, the implications of using fragility curves for compressor stations for the reduction cabins, as suggested in literature, were also addressed, and the necessity of developing specific fragilities was pointed out.