GNGTS 2014 - Atti del 33° Convegno Nazionale

GNGTS 2014 S essione 2.1 Conclusions. The article has pointed out that different horizontal ground motion definitions may have a strong impact on the predicted hazard. In particular, the largest differences in the hazard estimates are provided by ENV xy , which was largely used in the past [the 2004 national seismic hazard map (Gruppo di lavoro MPS, 2004), which is still adopted as reference map in the Italian code for building design, is based on this measure], and GM xy , which is currently the most widely used definition (e.g., Giardini et al. , 2013). As a consequence, old and new hazard maps based on different horizontal ground motion measures may be incompatible (i.e., non- comparable) to each other. Results presented here would be a warning for the researchers that will be involved in the assessment of the future seismic hazard map of Italy (or in the assessment of maps for local governments). As hazard maps have a paramount impact on design codes, urban planning, and risk mitigation strategies, analysts need to know since now from the engineering community what horizontal ground motion they have to take into account. In other words, we know what horizontal ground motion hazard was forecasted, we are well aware that different horizontal ground motions can be defined but we are eagerly waiting to know what horizontal ground motion hazard we will have to forecast. References Akkar S. and Bommer J.J.; 2010: Empirical equations for the prediction of PGA, PGV and spectral accelerations in Europe, the Mediterranean region and the Middle East . Seismological Research Letters, 81 , 195-206. Akkar S., Sandıkkaya M.A. and Bommer J.J.; 2014: Empirical ground-motion models for point- and extended-source crustal earthquake scenarios in Europe and the Middle East . Bulletin of Earthquake Engineering, 12 , 359-387. Ambraseys N.N., Simpson K.A. and Bommer J.J.; 1996: Prediction of horizontal response spectra in Europe . Earthquake Engineering and Structural Dynamics, 25 , 371-400. Barani S., Spallarossa D. and Bazzurro P.; 2009: Disaggregation of Probabilistic Ground-Motion Hazard in Italy . Bulletin of the Seismological Society of America, 99 , 2638-2661. Beyer K. and Bommer J.J.; 2006: Relationships between median values and between aleatory variabilities for different definitions of the horizontal component of motion . Bulletin of the Seismological Society of America, 96 , 1512- 1522. Bindi D., Massa M., Luzi L., Ameri G., Pacor F., Puglia R. andAugliera P.; 2013: Ground-motion prediction equations for the average horizontal component of PGA, PGV, and 5%-damped PSA at spectral periods up to 3.0 s using the RESORCE dataset . Bulletin of Earthquake Engineering, doi 10.1007/s10518-013-9525-5. Bindi D., Pacor F., Luzi L., Puglia R., Massa M., Ameri G. and Paolucci R.; 2011: Ground motion prediction equations derived from the Italian strong motion database . Bulletin of Earthquake Engineering, 9 , 1899-1920. Bommer J.J., Scherbaum F., Bungum H., Cotton F., Sabetta F. and Abrahamson N.A.; 2005: On the use of logic trees for ground-motion prediction equations in seismic hazard analysis . �������� �� ��� ������������� ������� �� Bulletin of the Seismological Society of America, 95 , 377-389. Boore D.M. and Atkinson G.M.; 2008: Ground motion prediction equations for the mean horizontal component of PGA, PGV and 5%-damped PSA at spectral periods between 0.01 s and 10.0 s . Earthquake Spectra, 24 , 99-138. Boore D.M., Stewart J.P., Seyhan E. and Atkinson G.M.; 2013: NGA-West2 equations for predicting response spectral accelerations for shallow crustal earthquakes . PEER Report 2013/05, Pacific Earthquake Engineering Research Center, University of California, Berkeley. Boore D.M., Watson-Lamprey J. and Abrahamson N.A.; 2006: Orientation-independent measures of ground motion . Bulletin of the Seismological Society of America, 100 , 1830-1835. Boore D.M.; 2010: Orientation-Independent, nongeometric-mean measures of seismic intensity from two horizontal components of motion . Bulletin of the Seismological Society of America, 96 , 1502-1511. Cauzzi C. and Faccioli E.; 2008: Broadband (0.05 to 20s) prediction of displacement response spectra based on worldwide digital records . ������� �� ����������� Journal of Seismology, 12 , 453-475. Dalguer L.A., Song S.G. and Baumann C.; 2012: Earthquake ground motion simulation (Kinematic and dynamic rupture models) . Deliverable No. 2a.3 of COGEAR (Coupled seismogenic GEohazards in Alpine Regions) Project, 50 pp. Giardini D., Woessner J., Danciu L., Cotton F., Crowley H., Grünthal G., Pinho R., Valensise G., Akkar S., Arvidsson R., Basili R., Cameelbeck T., Campos-Costa A., Douglas J., Demircioglu M. B., Erdik M., Fonseca J., Glavatovic B., Lindholm C., Makropoulos K., Meletti C., Musson R., Pitilakis K., Rovida A., Sesetyan K., Stromeyer D., Stucchi M.: 2013, Seismic Hazard Harmonization in Europe (SHARE): Online Data Resource, doi:10.12686/ SED-00000001-SHARE.