Characterization of site conditions (soil class, VS30, velocity profiles) for 33 stations from the French permanent accelerometric network (RAP) using surface-wave methods

• Published in: Bulletin of earthquake engineering Vol. 16; no. 6; pp. 2337 - 2365
• Main Authors: Hollender, Fabrice, Cornou, Cécile, Dechamp, Aline, Oghalaei, Kaveh, Renalier, Florence, Maufroy, Emeline, Burnouf, Clément, Thomassin, Sylvette, Wathelet, Marc, Bard, Pierre-Yves, Boutin, Vincent, Desbordes, Clément, Douste-Bacqué, Isabelle, Foundotos, Laetitia, Guyonnet-Benaize, Cédric, Perron, Vincent, Régnier, Julie, Roullé, Agathe, Langlais, Mickael, Sicilia, Deborah
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2018; Springer Nature B.V; Springer Verlag
• Subjects: Accelerometers; Broadband; Civil Engineering; Computation; Conditioning; Dispersion; Earth and Environmental Science; Earth Sciences; Environmental Engineering/Biotechnology; Geological hazards; Geophysics; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hazard assessment; High frequency; Hydrogeology; Methods; Original Research Paper; Rayleigh waves; Rocks; Sciences of the Universe; Seismic hazard; Seismic velocities; Soil; Soil conditions; Stations; Structural Geology; Surface waves; Surveying; Velocity; Velocity distribution; Velocity profiles; Vibration; Vibration analysis; Wave dispersion; Wave velocity; France; Velocity profile; Surface-wave methods; Accelerometric network; V; Epos-France
• ISSN: 1570-761X; 1573-1456
• DOI: 10.1007/s10518-017-0135-5

Data provided by accelerometric networks are important for seismic hazard assessment. The correct use of accelerometric signals is conditioned by the station site metadata quality (i.e., soil class, V S30 , velocity profiles, and other relevant information that can help to quantify site effects). In France, the permanent accelerometric network consists of about 150 stations. Thirty-three of these stations in the southern half of France have been characterized, using surface-wave-based methods that allow derivation of velocity profiles from dispersion curves of surface waves. The computation of dispersion curves and their subsequent inversion in terms of shear-wave velocity profiles has allowed estimation of V S30 values and designation of soil classes, which include the corresponding uncertainties. From a methodological point of view, this survey leads to the following recommendations: (1) perform both active (multi-analysis surface waves) and passive (ambient vibration arrays) measurements to derive dispersion curves in a broadband frequency range; (2) perform active acquisitions for both vertical (Rayleigh wave) and horizontal (Love wave) polarities. Even when the logistic contexts are sometimes difficult, the use of surface-wave-based methods is suitable for station-site characterization, even on rock sites. In comparison with previous studies that have mainly estimated V S30 indirectly, the new values here are globally lower, but the EC8-A class sites remain numerous. However, even on rock sites, high frequency amplifications may affect accelerometric records, due to the shallow relatively softer layers.