GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 a) b) Figure 3. Representation of the Mw 6.4 1976 Friuli earthquake peak ground velocity field #12 (a) and 95th percentile average consequence radius for the pipe #048 (b). Conclusions In this work, the proposal of a probabilistic framework for seismic risk assessment of buried pipeline systems located in areas prone to seismic hazard was proposed. Seismic hazard modeling coupled with a description of pipelines seismic vulnerability in terms of release states lead to estimate potential consequences in terms of network release scenarios in case of quake occurrence. In particular, for each pipe segment release probabilities were assessed through fragility functions, according to the specific level of shaking induced by the quake, thus leading to different values along the same pipes. Then, event tree analysis allowed to quantify probabilities of occurrence of the different possible consequences of pipe structural failure. The proposed approach was tested through the simulation of the effects on a pipe belonging to the Italian National gas distribution system located in northeast Italy. Once defined a probable earthquake scenario on the basis of the recent seismicity of the area, a set of 100 spatially correlated PGV fields were simulated and for each of them consequences were assessed. Results allowed to identify segments of the pipe mostly affected in case of scenario occurrence. References Bindi, D., Pacor, F., Luzi, L., Puglia, R., Massa, M., Ameri, G., & Paolucci, R. (2011). Ground motion prediction equations derived from the Italian strong motion database. Bulletin of Earthquake Engineering, 9(6), 1899-1920. Boore D.M., Gibbs J.F., Joyner W.B., Tinsley J.C., Ponti D.J. (2003) Estimated ground motion from the 1994 Northridge, California, earthquake at the site of the Interstate 10 and La Cienega Boulevard bridge collapse, West Los Angeles, California. Bulletin of the Seismological Society of America 93(6), 2737–2751.