GNGTS 2019 - Atti del 38° Convegno Nazionale

450 GNGTS 2019 S essione 2.2 Although the results of the probabilistic approach are site- dependent, one can recognise homogeneous macro areas in terms of seismic hazard (which means same probability of events with similar PGA for a fixed return period) where the displacement hazard curves exhibit a narrow spatial variability. Central Italy and Emilia can be reasonably considered homogeneous zones, for which a lower and upper bounds displacement hazard curves are identified, as illustrated in Fig. 3. The annual rate of exceedance of a displacement level d is greater for Central Italy than Emilia as the first one is characterised by a higher seismic hazard. In other words, the probabilities of occurrence of a permanent sliding displacement in two similar slopes located in two different sites solely differ for the specific site seismic hazard. The probabilistic framework adopted in this study provides a useful tool to evaluate the seismic performance of a slope in terms of permanent sliding displacements. Further investigations will be addressed to determine the displacement hazard curves for different values of the yield seismic coefficient to introduce, though in a simplified way, the strength of the slope against sliding. Finally, a two-parameters probabilistic approach will be develop, based on the more reliable semi-empirical relationships linking the permanent displacements to a couple of strong motion parameters for fixed yield seismic coefficients. References Cornell C. A., Luco N.; 2001: Ground motion intensity measures for structural performance assessment at near-fault sites . In Proc. US–Japan joint workshop and third grantees meeting, US–Japan Coop. Res. on Urban EQ. Disaster Mitigation, Seattle, Washington. Gaudio D., Rauseo R., Rampello S.; 2019: Equivalent seismic coefficient for slopes from updated semi-empirical relationship . Submitted for publication. Newmark N. M.; 1965: Effects of earthquakes on dams and embankments . Geotechnique, 15(2), 139-160. Rampello S., Callisto L.; 2008: Stabilità dei pendii in condizioni sismiche . In: Patron (ed) Opere Geotecniche in condizioni sismiche , XII Ciclo di Conferenze di Meccanica e Ingegneria delle Rocce, Bologna, pp 241-271. Rampello S., Callisto L., Fargnoli P.; 2010: Evaluation of slope performance under earthquake loading conditions. Rivista Italiana di Geotecnica, XLIV (4):29-41. Rathje E. M., Cho Y.; 2019: Probabilistic assessment of the earthquake-induced displacements of a slope using finite element analysis . Proceeding of the 7 th International Conference on Earthquake Geotechnical Engineering, Rome, Italy. Rathje E. M., Wang Y., Stafford P. J., Antonakos G., Saygili G.; (2014): Probabilistic assessment of the seismic performance of earth slopes . Bulletin of Earthquake Engineering, 12 (3), 1071-1090. Saygili G., Rathje E. M.; 2008: Empirical predictive models for earthquake-induced sliding displacements of slopes . Journal of Geotechnical and Geoenvironmental Engineering, 134(6), 790-803. Fig. 3 - Displacement hazard curves – lower and upper bounds for Emilia and Central Italy.